Here, I used regular expression to remove White space and Tab. You can easily understand the code, it very simple.
<html>
<head>
<title>Trim Example</title>
<script type="text/javascript">
function rtrim(str)
{
if(str=='') return '';
var rReg= /[\t \s]+$/;
return str.replace(rReg,'');
}
function ltrim(str)
{
if(str=='') return '';
var rReg= /^[\t \s]+/;
return str.replace(rReg,'');
}
function trim(str)
{
if(str=='') return '';
str = rtrim(str);
return ltrim(str);
}
function check()
{
var val =document.getElementById('user').value
val = trim(val);
alert(val.length);
}
</script>
<body>
<input type="text" id="user" name="user" value='' />
<input type="button" name="button" value="check" onclick="check();">
</body>
</html>
<html>
<head>
<title>Trim Example</title>
<script type="text/javascript">
function rtrim(str)
{
if(str=='') return '';
var rReg= /[\t \s]+$/;
return str.replace(rReg,'');
}
function ltrim(str)
{
if(str=='') return '';
var rReg= /^[\t \s]+/;
return str.replace(rReg,'');
}
function trim(str)
{
if(str=='') return '';
str = rtrim(str);
return ltrim(str);
}
function check()
{
var val =document.getElementById('user').value
val = trim(val);
alert(val.length);
}
</script>
<body>
<input type="text" id="user" name="user" value='' />
<input type="button" name="button" value="check" onclick="check();">
</body>
</html>
