Check Whether A Textbox Value Is Numeric Or String

Possible Duplicate: Is there a (built-in) way in JavaScript to check if a string is a valid number? i want to check whether a textbox contains a numeric value or a string using

Solution 1:

Update: Looking back at my own answer, I realise the problem with it. You can't compare with NaN, you need to use isNaN function:

var query=getquerystring();
if(isNaN(parseFloat(query))
{
   alert("query is a string");
}
else{
   alert("query is numeric");
}

Or, alternatively, you can use regex pattern matching to see if the string matches what it should.