asked on

validating a text field!!!

hai all,

I have textbox for user to key in product_id, I wanted to check the following while keyin itself(it is a alphanumeric value)
1)first two characters should be alphabets.
2)remaining should b numeric.
3)user should not key in beyond 13 characters.

how am I go about it? can any one feed back to me.

zvonko

How about this:
<html>
<head>
<script>
function checkField(event, thisField) {
thischar = (event.which) ? event.which : event.keyCode;
if(thischar < 32) return true;
if(thischar > 90) return false;
if(thischar < 48) return false;
if(thisField.value.length < 2) {
if(thischar > 64) return true;
alert('Only A-Z in first two positions.')
return false;
}
return true;
}
</script>
</head>
<body>
<form>
<input type=text size=13 maxlength=13 onKeyDown="return checkField(event, this)">
</form>
</body>
</html>

Good luck,
zvonko

CJ_S

Another one which also works in Netscape:

function checktextbox(tObj)
{
sVal = tObj.value;
sTmp = "";
sAlpha = "abcdefghijklmnopqrstuvwxyz";
sNumeric = "1234567890";

bFalse = false;
for(i=0;i<sVal.length;i++)
{
if(i<2 && sAlpha.indexOf(sVal.charAt(i))<0)
bFalse = true;
else
sTmp += sVal.charAt(i);
if(i>=2 && sNumeric.indexOf(sVal.charAt(i))<0)
bFalse = true;
else
sTmp += sVal.charAt(i);
}
tObj.value = sTmp;
}

with:

<input type=text onKeyUp="checktextbox(this)" maxlength=13>

CJ_S

Can be shorter:

function checktextbox(tObj)
{
sVal = tObj.value;
sTmp = "";
sAlpha = "abcdefghijklmnopqrstuvwxyz";
sNumeric = "1234567890";

bFalse = false;
for(i=0;i<sVal.length;i++)
{
if(i<2 && sAlpha.indexOf(sVal.charAt(i))>=0)
sTmp += sVal.charAt(i);
if(i>=2 && sNumeric.indexOf(sVal.charAt(i))>=0)
sTmp += sVal.charAt(i);
}
tObj.value = sTmp;
}

CJ_S

and this one can be gone:
bFalse = false;

manju70

ASKER

hai zvonko,
Thank you for ur reply

can u please give me the feed back as for what u check the first 3 if condititons.

actually I tried ur coding , it doesn't accepts key in numbers for first two characters. but can accept keyin alpabets for remaining 11 characters.(actually I require remaining 11 should accept only alphabets)

expecting ur reply.
manju

manju70

ASKER

sorry remaining 11 characters should accept only numbers.

manju

manju70

ASKER

sorry remaining 11 characters should accept only numbers.

manju

ASKER CERTIFIED SOLUTION

zvonko

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zvonko

Second active alert is a nonsense :)

It should read:
alert('Only 0-9 after first two positions.')

The first commented alert is to test key values you like to add to checking.

Cheers,
zvonko

zvonko

Thanks for the points manju70 :)

How does my code work for you?

manju70

ASKER

yah it works the way I expected.Thanks & hats off.