integer entry only

[Tracey]

hi..

I would like to validate users input into a form, allowing only the number keys (eg no negatives or decimals)

I have found some basic code which traps out numbers using isNaN, but this allows -ve and decimals. could someone help me extend this to allow only +ve integers??? I have tried using this function on keypress, onkeyup etc but isnt quite right.

<script language=&quot;javascript&quot;>
<!--
function validate(txtbox)
{
    if (isNaN(txtbox.value) || txtbox.value==&quot;&quot;) {
        alert(&quot;Invalid Entry!&quot;);
        txtbox.focus();
    } else {
        alert(&quot;Do whatever you would do for a proper entry!&quot;);
    }
        
}
//-->
</script>
<form>
<input type=&quot;text&quot; name=&quot;entry&quot; onchange=&quot;validate(this.form.entry);&quot;>
<input type=&quot;button&quot;>
</form>

 

[trollacious]

var valid=true, number=txtbox.value

//important to check for NaN first
if (isNaN(number)) valid=false;
//check for length, not null string, because number==0 is same as number==""
else if (number.length=0) valid=false;
else if (Math.round(number)!=number) valid=false;
else if (number <= 0) valid=false;
//add more conditions here if wanted

if (!valid)
{
alert(&quot;Invalid Entry!&quot;
txtbox.focus();
}
else
{
alert(&quot;Do whatever you would do for a proper entry!&quot;
}

 

[Tracey]

wow thanks trollacious, just what the doctor ordered