function trim(txt) {
    txt = txt.replace(/^(\s)+/, '');
    txt = txt.replace(/(\s)+$/, '');
   	return txt;
}
function validateEmail(objemail) 
{
	var email;
	email=objemail.value;
	if (trim(email) == '') {
		return true;
	} else {
		var emailExp = new RegExp("^[\\w\\-\\.]+\\@[\\w\\-]+\\.[\\w\\-]+");
		if (emailExp.test(email))  
		{
			return true;
		} 
		else 
		{
			alert('Du lieu nhap vao khong phai dia chi mail !');
			objemail.focus();
			return false;
		}
	}
}
function isValidDate(strDate)
{    
  var retval = 0    
  var aDDMMCCYY    
  var dtest    
  // Kiem tra dung format    
  if (/^(\d\d?-\d\d?-\d{4})|(\d\d?\/\d\d?\/\d{4})|(\d{8})$/.test(strDate))    
  {    
    if (/\//.test(strDate))    
    {    
      aDDMMCCYY = strDate.split("/");    
    }    
    else    
    if (/-/.test(strDate))    
    {    
      aDDMMCCYY = strDate.split("-");    
    }    
    else    
    {    
      aDDMMCCYY = Array(strDate.substr(0,2), strDate.substr(2,2), strDate.substr(4,4))    
    }        
	dtest = new Date(aDDMMCCYY[1] + "/" + aDDMMCCYY[0] + "/" + aDDMMCCYY[2]);          
	
	if (aDDMMCCYY[2] >= 1900)
	{
		if (dtest.getDate() != aDDMMCCYY[0] || dtest.getMonth() +1 != aDDMMCCYY[1] || dtest.getFullYear() != aDDMMCCYY[2])    
		{    
			retval = 2    			
		}    
	}else{
		retval = 3
	}
  }    
  else    
  {    
	retval = 1    
  }    
  return retval    
}    
function isBlank(obj)
{
	if (obj.length <1 || obj.value=="")
		return true;
	else
		return false;
}

function CheckDateOnBlur(obj)    
{   
	if (!isBlank(obj))    
	{    
		if (isValidDate(obj.value)!=0)    
		{	
			alert('Ngày ' + obj.value + ' không hợp lệ. Bạn phải nhập ngày theo dạng dd/MM/yyyy.')    
			obj.focus();
			return false;
		}    
	}    
	return true;

}
function ValidateNumeric() 
{ 
	var keyCode = window.event.keyCode; 
	if (keyCode > 57 || keyCode < 48)
		window.event.returnValue = false; 
}
function CheckNull()
{
	var i;
	var str;
	var obj;
			
	for (i=0;i<window.document.forms(0).length-1;i++)
	{
		obj=window.document.forms(0).item(i);
		
			if (obj.IsNull == 'NotNull' && obj.value=='')
			{
				alert('Vui long nhap lieu!')    
				obj.focus();
				return false;
			}
	}
	return true;
}

function isInteger(numString) {
	if (isNaN(numString)) {
		return false;
	} else {
		return (numString.indexOf('.') > 0) ? false : true;
	}
}
function checkNumber(txt)
{
	if (txt.value !='')
	{
		var numString =txt.value;
		if (!isInteger(numString))
		{
			alert('Vui long nhap so');
			txt.focus();
		}
	}
}
function CheckHTMLTags()
{
	var i;
	var str;
	var obj;
				
	for (i=0;i<window.document.forms(0).length-1;i++)
	{
		obj=window.document.forms(0).item(i);
		
			if (obj.NoHTMLTag == '1' && ((obj.value.indexOf('<')!=-1)||(obj.value.indexOf('>')!=-1)))
			{
				alert('Vui long khong nhap ky tu dac biet!')    
				obj.focus();
				return false;
			}
	}
	return true;
}
function checkHTMLTag(txt)
{
	if ((txt.value.indexOf('<')!=-1)||(txt.value.indexOf('>')!=-1))
	{
		alert('Vui long khong nhap ky tu dac biet');
		txt.focus();
	}
}