How to check textfield for whitespaces in jquery

Question

I have a form. I want to put validation so that It will check if user enters white spaces or not. If its white spaces then show error. How could I do this?

Answer 1

In case you want to detect if there is any white space all through the user's input string,

var str = $("input").val();
if( str.indexOf(" ") !== -1 )
{
    alert("bad input");
}

Example: http://jsfiddle.net/pYquc/