function check_login(Login1){
	if (document.Login1.username1.value=='')
	{    
			alert('Chua  nhap ten dang nhap !');
			document.Login1.username1.focus();  
			return false;
	}	
	

	if (document.Login1.password1.value=='')
	{    
			alert('Chua  nhap mat khau !');
			document.Login1.password1.focus();  
			return false;
	}	

	if (document.Login1.mabaove.value=='')
	{    
			alert('Chua nhap ma bao ve  !');
			document.Login1.mabaove.focus();  
			return false;
	}


}

function check_timkiem(timkiem){
	if (document.timkiem.tim.value=='')
	{    
			alert('Chua  nhap gia tri de tim !');
			document.timkiem.tim.focus();  
			return false;
	}	
	
}

function check_dangtin(dangtin){
	if (document.dangtin.ten2.value=='')
	{    
			alert('Chua nhap ten chung khoan !');
			document.dangtin.ten2.focus();  
			return false;
	}


	if (document.dangtin.soluong2.value!='')
	{    
			if (isNaN(document.dangtin.soluong2.value))
			{
			alert('So luong phai la dang so !');
			document.dangtin.soluong2.focus();  
			return false;
			}
	}

	if (document.dangtin.gia2.value!='')
	{    
			if (isNaN(document.dangtin.gia2.value))
			{
			alert('Gia phai la dang so !');
			document.dangtin.gia2.focus();  
			return false;
			}
	}
}

function check_daugia(daugia){
	if (document.daugia.ten2.value=='')
	{    
			alert('Chua nhap ten chung khoan !');
			document.daugia.ten2.focus();  
			return false;
	}


	if (document.daugia.soluong2.value!='')
	{    
			if (isNaN(document.daugia.soluong2.value))
			{
			alert('So luong phai la dang so !');
			document.daugia.soluong2.focus();  
			return false;
			}
	}

	if (document.daugia.gia2.value!='')
	{    
			if (isNaN(document.daugia.gia2.value))
			{
			alert('Gia phai la dang so !');
			document.daugia.gia2.focus();  
			return false;
			}
	}
	
}

function check_doimatkhau(doimatkhau)
{	

	if (document.doimatkhau.ho_ten.value=='')
	{    
			alert('Chua nhap ho ten !');
			document.doimatkhau.ho_ten.focus();  
			return false;
	}

	if (document.doimatkhau.matkhaucu.value=='')
	{    
			alert('Chua nhap mat khau cu !');
			document.doimatkhau.matkhaucu.focus();  
			return false;
	}
	
	if (document.doimatkhau.matkhaumoi.value=='')
	{    
			alert('Chua nhap mat khau moi !');
			document.doimatkhau.matkhaumoi.focus();  
			return false;
	}

	if (document.doimatkhau.matkhaumoi.value != document.doimatkhau.xacnhanlai.value)
	{    
			alert('Xac nhan mat khau moi khong dung !');
			document.doimatkhau.xacnhanlai.focus();  
			return false;
	}


	if (document.doimatkhau.di_dong.value=='')
	{    
			alert('Chua nhap so dien thoai di dong !');
			document.doimatkhau.di_dong.focus();  
			return false;
	}
	else
	{
		if (isNaN(document.doimatkhau.di_dong.value))
		{
			alert('So dien thoai di dong phai la dang so !');
			document.doimatkhau.di_dong.focus();  
			return false;		
		}
	}


	
	if (document.doimatkhau.email.value=='')
	{    
	}	
	else{
			var s = document.doimatkhau.email.value;
			var tim;
			var kq;
			tim=/@/i;
			kq=s.search(tim);
			if(kq==-1){
				alert('Dia chi email phai co chu @');
				document.doimatkhau.email.focus();  
				return false;
			}
	
	}	


}