Java Script - onBlur event giving problem

I have a web page that need validation of input data ..
and i have used onBlur event that calls ValidateField
that checks whether the length of entered data in that
field is greater than certain value(say 3 chars)..

<INPUT NAME="FirstName" TYPE=TEXT SIZE=15 onBlur="validateField(this,3);" >

function ValidateField(field,len)
{
if (field.length < len)
{
alert("Field must be at least " + minLen + "
characters long!");
field.focus();
}
}

But, the problem is, the message keeps coming
infinitely if less characters, say 2 chars is entered..
It goes into infinite message display and it

I've answered this in the javascript forum

If you want to post to more that one forum please post the question in one forum and then just post a link to it in the other forum(s)

hi mark,
i am sorry, i posted at two places..
you are perfectly right in that there are
two successive text boxes, first name, last name
using these validations..

Do you know any solution to get around the message
problem ??
thanks
sarath