function validateForm(fObj)
{
	var chk_result = true;
	var msg = "";
	hideAllErrors(fObj);

	for (var i = 0; i < fObj.elements.length; i++)
	{
		if (fObj.usr_subj.options[fObj.usr_subj.selectedIndex].value != 0 && fObj.elements[i].name == "usr_tnum") continue;
		if (fObj.elements[i].name == "usr_phone") continue;
		if (0 == fObj.elements[i].value.length)
		{
			msg += displayError(fObj.elements[i], "This field is required.");
			chk_result = false;
		}
	}

	with (fObj)
	{
		if (usr_email.value.length > 0 && !(/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/).test(usr_email.value))
		{
			msg += displayError(usr_email, "Check up correctness of input of an e-mail address.");
			chk_result = false;
		}
		
		var tnum=usr_tnum.value
		while(tnum.length>0 && tnum.substring(0,1)=="0") tnum = tnum.substring(1)
		if (usr_subj.options[usr_subj.selectedIndex].value == 0 && (isNaN(parseInt(tnum)) || parseInt(tnum) != tnum))
		{
			msg += displayError(usr_tnum, "Transaction number must be a number.");
			chk_result = false;
		}
	}

	if (msg.length > 0)
		alert("Errors found:\n\n" + msg);

	return chk_result;
}

function displayError(obj, msg)
{
	var errBlock = document.getElementById(obj.id + "-err");
	if (null == errBlock)
	{
		return "  • " + msg + "\n";
	}
	else
	{
		errBlock.innerHTML = msg;
		errBlock.style.display = "block";
		return "";
	}
}

function hideAllErrors(fObj)
{
	for (var i = 0; i < fObj.elements.length; i++)
	{
		var errBlock = document.getElementById(fObj.elements[i].id + "-err");
		if (null != errBlock)
		{
			errBlock.innerHTML = "";
			errBlock.style.display = "none";
		}
	}
}

function showAllErrors(fObj)
{
	for (var i = 0; i < fObj.elements.length; i++)
	{
		var errBlock = document.getElementById(fObj.elements[i].id + "-err");
		if (null != errBlock && errBlock.innerHTML.length != 0)
			errBlock.style.display = "block";
	}
}