function trim1(inputString)
{
    if (typeof inputString != "string")
    {
        return inputString;
    }
    var retValue = inputString;
    var ch = retValue.substring(0, 1);
    while (ch == " ")
    { // Check for spaces at the beginning of the string
        retValue = retValue.substring(1, retValue.length);
        ch = retValue.substring(0, 1);
    }
    ch = retValue.substring(retValue.length-1, retValue.length);
    while (ch == " ")
    { // Check for spaces at the end of the string
        retValue = retValue.substring(0, retValue.length-1);
        ch = retValue.substring(retValue.length-1, retValue.length);
    }
    //while (retValue.indexOf(" ") != -1) { // Note that there are two 
 //spaces in the string - look for multiple spaces within the string
    //retValue = retVal
//}
return retValue;
}

var vld_Email =  
/^(([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,5}|[0-9]{1,3})(\]?))?$/;

function validate()
    {
		var pattern = /^[a-zA-Z0-9_]*$/;
        if(trim1(document.form1.user_name.value)=="")
        {
            alert("Please enter your username")
            document.form1.user_name.focus();
            return false;
        }
		
		else if(trim1(document.form1.password.value)=="")
        {
            alert("Please enter your password")
            document.form1.password.focus();
            return false;
        }
		else if(!pattern.test(document.form1.password.value))
		{
			alert("Invalid password value");
			document.form1.password.focus();
			return false;
		}	

	    
		
	   else
        {
         document.form1.submit();
        }
    }