Javascript Validate Float Number

This is a simple function for Validate Float Number like currency validation. Just copy the following code into the html page and useit.

<!--
 Floadtng point validation code by samplephpcodes.com

  Valid inputs      1234       12234.0   123456.0000   0.1213

  Invalis Inputs    dada       1313.     .34343 	

-->
<script language="javascript">
function validate() {  

	var strPattern = '^\[0-9]+(\.\?[0-9]+)?$';  

	if(document.form1.txt.value.search(strPattern)== -1)
	{
		alert('Not a Valid currency Format$');
		document.form1.txt.focus();
		return false;
        }else return true;

}
</script>