Solved

autochecking checkbox based on form field being filled in

Posted on 2004-10-20
12
269 Views
Last Modified: 2010-08-05
hi all,
I have a page that contains a quantity field as well as an 'add' checkbox field that users use to add the item to their shopping cart. I want to get rid of this checkbox requirement by having it autocheck when a value is entered in to the quantity field. What would be the correct syntax to do this?

Here's a code snippet that's currently on the page:

<input type="text" name="Qty" size="4" maxlength="4" value="">
 
<input type="checkbox" name="AddBook" value="#ISBN#"> I need this form element to both autocheck when a form quantity field is entered in. I also need this checkbox to be hidden as well.

Thanks!
0
Comment
Question by:bluskyGuy
  • 4
  • 4
  • 2
  • +2
12 Comments
 
LVL 15

Expert Comment

by:justinbillig
Comment Utility
<input type="text" name="Qty" size="4" maxlength="4" value="" onchange="if(this.value != ''){ formname.AddBook.checked=true;}else{formname.AddBook.checked=false;}">
0
 
LVL 15

Expert Comment

by:justinbillig
Comment Utility
<div style="visibility: hidden"><input type="text" name="Qty" size="4" maxlength="4" value=""></div>
0
 
LVL 8

Accepted Solution

by:
RozanaZ earned 500 total points
Comment Utility
Checkboxes are visible:

<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<script>
      function test(obj, checkId)
      {
            if (obj.value != "")
            {
                  document.getElementById(checkId).checked = true;
            }
            else
            {
                  document.getElementById(checkId).checked = false;
            }
      }      
</script>
</HEAD>
<BODY>
<form>
      <input type="checkbox" name="AddBook" id="book1" value="#ISBN#">
      <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book1')">
      <br>
      <input type="checkbox" name="AddBook" id="book2" value="#ISBN#" >
      <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book2')">
      <br>
      <input type="checkbox" name="AddBook" id="book3" value="#ISBN#" >
      <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book3')">
</form>
</BODY>
</HTML>

-------------------

Checkboxes invisible:


<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<script>
      function test(obj, checkId)
      {
            if (obj.value != "")
            {
                  document.getElementById(checkId).checked = true;
            }
            else
            {
                  document.getElementById(checkId).checked = false;
            }
      }      
</script>
</HEAD>
<BODY>
<form>
      <input type="checkbox" name="AddBook" id="book1" value="#ISBN#" style="display:none">
      <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book1')">
      <br>
      <input type="checkbox" name="AddBook" id="book2" value="#ISBN#" style="display:none">
      <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book2')">
      <br>
      <input type="checkbox" name="AddBook" id="book3" value="#ISBN#" style="display:none">
      <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book3')">
</form>
</BODY>
</HTML>
0
 
LVL 36

Expert Comment

by:Zyloch
Comment Utility
Hi bluskyGuy,

Something like this?

I guess you would call this on onchange inside the textbox, like this: checkTxtField(this);

function checkTxtField(obj) {
   for (var i=0;i<obj.form.elements.length;i++) {
      if (obj.form.elements[i]==obj) {
         if (obj.value!="") {
            obj.form.elements[i+1].checked=true;
            obj.form.elements[i+1].style.visibility='hidden';
         } else {
            obj.form.elements[i+1].checked=false;
            obj.form.elements[i+1].style.visibility='visible';
         }
         break;
      }
   }
}

Regards,
Zyloch
0
 
LVL 32

Expert Comment

by:ldbkutty
Comment Utility
without a trim you will get checked even if you enter a white space in the textbox. you will need both onkeyup as well as onchange event (to make sure the checkbox is checked even if copy, paste the values in the textbox).

<html>
<head>
<script language="JavaScript" type="text/javascript">
<!--
function makeChecked() {
 var theForm = document.myform;
 if(trim(theForm.Qty.value) != "")
   theForm.AddBook.checked = true;
 else
   theForm.AddBook.checked = false;
}
function trim(str) {
  return str.replace(/^\s*|\s*$/g,"");
}
//-->
</script>
</head>
<body>
<form name="myform" method="post" action="" >
Quantity: <input type="text" name="Qty" size="4" maxlength="4" value="" onkeyup="makeChecked()" onchange="makeChecked()"/> <br>
Add: <input type="checkbox" name="AddBook" value="#ISBN#"/>
</form>
</body>
</html>
0
 
LVL 8

Expert Comment

by:RozanaZ
Comment Utility
yes, I agree with ldbkutty
trim should be used

<HTML>
<HEAD>
<TITLE></TITLE>
<script>
     function test(obj, checkId)
     {
          if (obj.value.trim != "")
          {
               document.getElementById(checkId).checked = true;
          }
          else
          {
               document.getElementById(checkId).checked = false;
          }
     }    
</script>
</HEAD>
<BODY>
<form>
     <input type="checkbox" name="AddBook" id="book1" value="#ISBN#" style="display:none">
     <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book1')">
     <br>
     <input type="checkbox" name="AddBook" id="book2" value="#ISBN#" style="display:none">
     <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book2')">
     <br>
     <input type="checkbox" name="AddBook" id="book3" value="#ISBN#" style="display:none">
     <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book3')">
</form>
</BODY>
</HTML>
0
Enabling OSINT in Activity Based Intelligence

Activity based intelligence (ABI) requires access to all available sources of data. Recorded Future allows analysts to observe structured data on the open, deep, and dark web.

 
LVL 8

Expert Comment

by:RozanaZ
Comment Utility
bluskyGuy ,
Do you want a number validation for quantity field?
0
 

Author Comment

by:bluskyGuy
Comment Utility
Thanks all for the recommendations. I'm giving them a shot now.
If you could give me a number validation for the quantity field that would be great!
Thanks again!
0
 
LVL 8

Expert Comment

by:RozanaZ
Comment Utility
<HTML>
<HEAD>
<TITLE></TITLE>
<script>
     function test(obj, checkId)
     {            
              if (isNaN((obj.value)))
              {
                  alert("Numbers only");
                  obj.focus();
                  return;
              }
              if (obj.value != "")
          {
            
               document.getElementById(checkId).checked = true;
          }
          else
          {
               document.getElementById(checkId).checked = false;
          }
     }  
</script>
</HEAD>
<BODY>
<form>
     <input type="checkbox" name="AddBook" id="book1" value="#ISBN#" style="display:none">
     <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book1')">
     <br>
     <input type="checkbox" name="AddBook" id="book2" value="#ISBN#" style="display:none">
     <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book2')">
     <br>
     <input type="checkbox" name="AddBook" id="book3" value="#ISBN#" style="display:none">
     <input type="text" name="Qty" size="4" maxlength="4" value="" onChange="test(this, 'book3')">
</form>
</BODY>
</HTML>
0
 

Author Comment

by:bluskyGuy
Comment Utility
For some reason the checkboxes aren't autochecking themselves.
I'm using this for the qty field syntax:
 <input type="text" name="Qty" size="4" maxlength="4" value="" onchange="if(this.value != ''){ formname.AddBook.checked=true;}else{formname.AddBook.checked=false;}">

Any suggestions?
0
 

Author Comment

by:bluskyGuy
Comment Utility
the autocheckbox is now working! The issue that I notice is that the user has to click out of the qty field box in order for the checkbox to be checked...do you know how to make it so that as soon as a number is entered in the checkbox is checked?
0
 

Author Comment

by:bluskyGuy
Comment Utility
Nevermind, i solved the problem!
Thanks everyone for the help!
0

Featured Post

IT, Stop Being Called Into Every Meeting

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

Join & Write a Comment

JavaScript can be used in a browser to change parts of a webpage dynamically. It begins with the following pattern: If condition W is true, do thing X to target Y after event Z. Below are some tips and tricks to help you get started with JavaScript …
International Data Corporation (IDC) prognosticates that before the current the year gets over disbursing on IT framework products to be sent in cloud environs will be $37.1B.
The viewer will learn the basics of jQuery, including how to invoke it on a web page. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery.: (CODE)
The viewer will learn the basics of jQuery including how to code hide show and toggles. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery…

763 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

5 Experts available now in Live!

Get 1:1 Help Now