darby
asked on
Checking a number is entered
Is there any easy way of checking that a number is entered rather than a letter ??
I get string error if someone enters a letter where a number should be...
Thanks
dean..
I get string error if someone enters a letter where a number should be...
Thanks
dean..
Use below JavaScript function to test if the field is numeric.
<script language="JavaScript">
<!--
// check if string is numeric
function IsNumeric(string)
{
var i;
var nLength = string.length;
var valid = true;
for ( i=0; i<nLength; i++ )
{
if ( string.charAt(i) >= '0' && string.charAt(i) <= '9' )
continue;
else
{
valid = false;
break;
}
}
return valid;
}
function validate_form(form)
{
if ( !IsNumeric(form.txtAge.val
{
alert("Please enter an integer for age");
return false;
}
else
return true;
}
//-->
</script>
...
<form name="frmMain" method="post" action="second_page.asp" onsubmit="return validate_form(this)">
Age: <input type="text" name="txtAge">
<br>
<input type="submit">
</form>
hongjun
<script language="JavaScript">
<!--
// check if string is numeric
function IsNumeric(string)
{
var i;
var nLength = string.length;
var valid = true;
for ( i=0; i<nLength; i++ )
{
if ( string.charAt(i) >= '0' && string.charAt(i) <= '9' )
continue;
else
{
valid = false;
break;
}
}
return valid;
}
function validate_form(form)
{
if ( !IsNumeric(form.txtAge.val
{
alert("Please enter an integer for age");
return false;
}
else
return true;
}
//-->
</script>
...
<form name="frmMain" method="post" action="second_page.asp" onsubmit="return validate_form(this)">
Age: <input type="text" name="txtAge">
<br>
<input type="submit">
</form>
hongjun
Just another approach.
hongjun
hongjun
ASKER CERTIFIED SOLUTION
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Hey DanniC,
Please read the information regarding the distinction between comments and answers below and on the link when you submit a post. Once you propose an answer, experts who haven't posted to this thread will be unable to participate.
Most experts post as comments even when they are certain that they are answering the question. The person posing the question can accept a comment as an answer at any time.
Fritz the Blank
Please read the information regarding the distinction between comments and answers below and on the link when you submit a post. Once you propose an answer, experts who haven't posted to this thread will be unable to participate.
Most experts post as comments even when they are certain that they are answering the question. The person posing the question can accept a comment as an answer at any time.
Fritz the Blank
My apologize to fritz_the_blank, hongjun and darby.
ASKER
You know why :)
ASKER
Ok Fritz.
Your solutions works on a single input, but i think i might be making it a little harder.
the form is generated by a database, and creates multiple input boxes with the title 'quantity' when i try to get it to work with multiple boxes it gives an error.
So i guess i will have to try Dannic's server side - unless you know another way :)
Dean..
Your solutions works on a single input, but i think i might be making it a little harder.
the form is generated by a database, and creates multiple input boxes with the title 'quantity' when i try to get it to work with multiple boxes it gives an error.
So i guess i will have to try Dannic's server side - unless you know another way :)
Dean..
Hey Dean,
It may still be an easy thing using client-side JavaScript. Do all of the fields have similar names, i.e. quantity1, quantity2 and etc? If so, you can do something like this:
for (var i=0;i<document.form1.eleme
if (document.form1.elements[ i ].name.substring(0,7) == "quantity")
{
//do the error checking here
}
alert("Your Error Message");
}
If you want to give me the field names as dynamically generated by your script, I'll modify this to work for you.
Fritz the Blank
It may still be an easy thing using client-side JavaScript. Do all of the fields have similar names, i.e. quantity1, quantity2 and etc? If so, you can do something like this:
for (var i=0;i<document.form1.eleme
if (document.form1.elements[ i ].name.substring(0,7) == "quantity")
{
//do the error checking here
}
alert("Your Error Message");
}
If you want to give me the field names as dynamically generated by your script, I'll modify this to work for you.
Fritz the Blank
ASKER
Unfortunately they all have the same name, they are then put into an array i.e. 4 x boxes all called Quantity, generate an array of 1,2,3,4 etc. when passed to the next page.
Dean..
Dean..
ASKER
Thanks Dannic
Your solution suited they way i'd set my form up !!
Dean.
Your solution suited they way i'd set my form up !!
Dean.
Darby,
Were any of these comments helpful? If so, please select one as an answer.
Fritz the Blank
Were any of these comments helpful? If so, please select one as an answer.
Fritz the Blank
ASKER
Sorry
I'm sure i accepted it before, not just commented it...
I'm sure i accepted it before, not just commented it...
<HTML>
<HEAD>
<META NAME="GENERATOR" Content="Microsoft Visual Studio 6.0">
<TITLE></TITLE>
<SCRIPT LANGUAGE=javascript>
<!--
function NumberValidation()
{
strFieldValue = document.form1.text1.value
if(isNaN(strFieldValue))
{
alert(strFieldValue + " is not a number!");
}
}
//-->
</SCRIPT>
</HEAD>
<BODY>
<FORM action="" method=POST id=form1 name=form1><P> </P>
Test Input<INPUT type="text" id=text1 name=text1 >
<INPUT type="button" value="Button" id=button1 name=button1 onClick="JavaScript:Number
</FORM>
</BODY>
</HTML>