Using focus() with "this" keyword

[goe]

Hi,

Im my function I need to use focus() and select() based on the "this" keyword.

example:

[PHP]
onchange="validate(this)"

function validate(input) {
input.focus();
input.select();
}

[/PHP]

But for some reason above code doesn't work.
Could anybody help me with that?

Thank you,
goe

[anis2007]

<script>
function valid()
{
if(document.formname.fieldname.value=="")
{
alert("Show message here");
document.formname.fieldname.focus();
return false;
}
}

</script>
and call this function on click event, then this is focus on your field where you want.