function isValidEmailIn(string)
{
    if (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
        return true;
    else
        return false;
};

function isOnlyWhiteSpace(string)
{
    myRe = /^\s+$/;
    if ( (string == '') || (myRe.exec(string)) )
        return true;
    else
        return false;
};

function validate_form()
{
	$errMsg = "";
	
	with (document.forms['submitForm'])
	{
		if (isOnlyWhiteSpace(firstname.value)) 
		{ 
			$errMsg += "please provide a firstname.\n"; 
		}
		
		if (isOnlyWhiteSpace(surname.value)) 
		{ 
			$errMsg += "please provide a surname.\n"; 
		}
		
		if (isOnlyWhiteSpace(telephone.value)) 
		{ 
			$errMsg += "please provide contact number.\n"; 
		}
		
		if (!isValidEmailIn(emailaddress.value))
		{
			$errMsg += "please provide a valid email address.\n";
		}
		
		if (isOnlyWhiteSpace(comments.value)) 
		{ 
			$errMsg += "please enter your query.\n"; 
		}
	}

	if ($errMsg.length == 0)
	{
		// no errors
		return true;
	}
	else
	{
		// some errors
		alert($errMsg);
		return false;	
	}
};