Solved

Need an error msg if input is not numeric

Posted on 2008-06-20
6
535 Views
Last Modified: 2008-06-22
Hello,
  I am trying to use the code below to verify the input is numeric in value only.  The part I am having trouble developing is a function that gives a msg to the user if the input isn't numeric.  Please look over my code and help me out.  Thanks.
<head>

<style type="text/css">

.classname {

font-family: Verdana, Helvetica, sans-serif;

font-weight: bold;

font-size: 12pt;

color: red;

}

</style>

</head>
 

<body>
 

<form>

 <input name="Text1" type="text" />&nbsp;<input name="Button1" type="button" value="Validate" />

</form>
 

<script type="text/javascript">

function IsNumeric(sText) {

	var ValidChars = "0123456789.";

	var IsNumber=true;

	var Char;

	for (i = 0; i < sText.length && IsNumber == true; i++){

	Char = sText.charAt(i);

	if (ValidChars.indexOf(Char) == -1){

	IsNumber = false;

	}

  }

return IsNumber;

}

function CheckNumeric(field)

     {

          var check = true;

          var value = field.value; 

          for(var i=0;i < field.value.length; ++i)

          {

               var new_key = value.charAt(i); 

               if(((new_key < "0") || (new_key > "9")) && 

                    !(new_key == ""))

               {

                    check = false;

                    break;

               }

          }

          

          if(!check)

          {

               class="classname" ("Please enter a numeric value");

               

          }

     }

</script>
 

</body>
 

</html>

Open in new window

0
Comment
Question by:JDidit
  • 3
  • 2
6 Comments
 
LVL 41

Expert Comment

by:HonorGod
ID: 21836166
Something like this might be useful
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title> non-Digit </title>

<script type='text/javascript'>  

  //------------------------------------------------------------------

  // Name: nonDigit()

  // Role: Look for a non-digit in a value

  //------------------------------------------------------------------

  function check( obj ) {

    if ( /[^0-9]/.test( obj.value ) ) {

      alert( 'Invalid entry.  A non-digit was specified.' );

    }

  }

</script>  

</head>

<body>

  <input type='text' onchange='check(this);return false;' />

</body>

</html>

Open in new window

0
 
LVL 7

Expert Comment

by:alexpercsi
ID: 21836814
There is also the native isNaN function of Javascript. isNaN returns true if the value passed to it is not a numeric value. Example

if (isNaN(document.getElementById("tx_number").value))

alert("not a valid number");

else

//submit

Open in new window

0
 

Author Comment

by:JDidit
ID: 21837478
I'm not looking for an alert feature... this error will come up right below the input box in red I hope (I wrote the css code that way) to let the user know that they need to only put in numbers.  
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 
LVL 41

Accepted Solution

by:
HonorGod earned 250 total points
ID: 21838100
ok, no alert. what about something like:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title> non-Digit </title>

<script type='text/javascript'>  

  //------------------------------------------------------------------

  // Name: field()

  // Role: Locate the specified document element

  //------------------------------------------------------------------

  function field( id ) {

    var ele = document.getElementById( id );

    if ( !ele ) {

      alert( 'Specified document element not found.  id="' + id + '"' );

    }

    return ele;

  }
 

  //------------------------------------------------------------------

  // Name: nonDigit()

  // Role: Look for a non-digit in a value

  //------------------------------------------------------------------

  function check( obj ) {

    if ( /[^0-9]/.test( obj.value ) ) {

      var msg = field( 'msg' );

      if ( msg ) {

        msg.innerHTML = 'Invalid entry.  A non-digit was specified.';

      }

    }

  }

</script>  

</head>

<body>

  <input type='text' onchange='check(this);return false;' />

  <div id='msg'></div>

</body>

</html>

Open in new window

0
 

Author Comment

by:JDidit
ID: 21839450
That works great Thanks Honor!!!
0
 
LVL 41

Expert Comment

by:HonorGod
ID: 21840696
You are very welcome.  Thanks for the grade & points.

Good luck & have a great day
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article will give core knowledge of JavaScript and will head in to your first JavaScript program. I am Durvesh Naik and I am here to deal with this series of JavaScript. I will teach you JavaScript in part wise , as its quite boring to read big…
Having worked on larger scale sites, we found out that you are bound to look at more scalable solutions to integrating widgets, code snippets or complete applications and mesh them into functional sites, in any given composition. To share some of…
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…

911 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

20 Experts available now in Live!

Get 1:1 Help Now