function hasData(textbox, msg) {
	if (trimAll(textbox.value).length == 0) {
		alert(msg);
		textbox.focus();
		return false;
	}
	return true;
}

function trimAll(sString) {
	while (sString.substring(0,1) == ' ') {
		sString = sString.substring(1, sString.length);
	}
	while (sString.substring(sString.length-1, sString.length) == ' ') {
		sString = sString.substring(0,sString.length-1);
	}
	return sString;
}

function validate_email(email, response) {
    var retval = true;
    
    var invalidChars = new Array(" ",",","!","#","$","%","&","*","(",")");
    
    if(1 > email.value.indexOf("@")) {
       //alert("Your email must have a '@'."); 
       retval = false; 
    }
    else if(email.value.length == (email.value.indexOf("@")+1) ) {
       //alert("Your email must have a domain name after the '@'.");
       retval = false; 
    }
    else if(email.value.length == 0) { 
      //alert("Please enter your email."); 
      retval = false; 
    }
    
    for (i=0; i<invalidChars.length; i++) {
        if (-1 != email.value.indexOf(invalidChars[i])) {
            retval = false;
            break;
        }
    }

    if (!retval)
        alert(response);
    
    return retval;
}