Regular Expression in Javascript

[Anil Jain]

Friends!!
How do validate a word using regular expression in javascript, if i had to check that the word should have a only 1 alphabet and only 3 digits.
There should not be more more than one alphabet and 3 number and the first letter must be a letter.
eg.z999

Thanks

[Eric Pascarello]

Ah the fun world of reg exp
I am just learning this stuff....
see if this does the trick
<script>
function checkIt(Str) {
var StrRE = /^[a-zA-Z]\d\d\d/;
if (Str.match(StrRE)) {
return true;
}
else {
alert( "invalid!" );
return false; }
}
</script>
<input type="text" name="A" onchange="checkIt(this.value)">