// JavaScript Document
///////////////////Check Form Trong hoac NULL////////////////////////////////

function Trim(sString)
{
	while (sString.substring(0,1) == ' ')
	{
	sString = sString.substring(1, sString.length);
	}
	return sString;
	while (sString.substring(sString.length-1, sString.length) == ' ')
	{
	sString = sString.substring(0,sString.length-1);
	}
	return sString;
}
function validate_required(field,alerttxt)
{
with (field)
{
  if (Trim(value)==null||Trim(value)=="")
  {
  alert(alerttxt);return false;
  }
  else
  {
	
 	 return true;
  }
}
} 
///////////////////Check Form Trong hoac NULL////////////////////////////////
function validate_confirmpass(field,field2,alerttxt)
{
with (field)
{
  if (field.value!=field2.value)
  {
  alert(alerttxt);return false;
  }
  else
  {
	 
  return true;
  }
}
} 
///////////////////Check Form voi Value dai////////////////////////////////
function validate_length(field,alerttxt, lengthmax, lengthmin)
{
with (field)
{
  if (value.length >lengthmax || value.length < lengthmin )
  {
  alert(alerttxt);return false;
  }
  else
  {
  return true;
  }
}
} 
///////////////////Check Dinh Dang User////////////////////////////////
function validate_user(field,alerttxt)
{
with (field)
{
re = new RegExp();
re =/^\w+([\.-]?\w+)$/;
if (re.test(field.value) == false) 
  {alert(alerttxt);return false;}
else {return true;}
}
}
///////////////////Check Dinh Dang Email////////////////////////////////
function validate_email(field,alerttxt)
{
with (field)
{
re = new RegExp();
re =/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{1,4}){1,3}$/;
if (re.test(field.value) == false) 
  {alert(alerttxt);return false;}
else {return true;}
}
}


///////////////////Check Dinh Dang So////////////////////////////////
function validate_number(field,alerttxt)
{
with (field)
{
	if (isNaN(field.value)) 
	  {alert(alerttxt);return false;}
	else {return true;}
}
}
//////////////////////////////////////////////////////////

///////////////////Check Dinh Dang phone////////////////////////////////
function validate_Phone(field,alerttxt)
{
with (field)
{
re = new RegExp();
re =/^\+84.\d+([\.-]?\d([\-]?)+)$/;
if (re.test(field.value) == false) 
  {alert(alerttxt);return false;}
else {return true;}
}
}
//////////////check dinh dang ky tu/////////

//////////////////////////////////////////////////////
//Cach goi ham check form
//if (validate_required(user,"User must be filled out!")==false)
// {user.focus();return false;}
// Track key presses