function isBlank(Form){
	 
	 if(document.frmLogin.Username.value=="" || document.frmLogin.Password.value==""){
	       if(document.frmLogin.Username.value=="" && document.frmLogin.Password.value==""){
	          alert("Please enter Username and Password!");
			  return false;
		   }if(document.frmLogin.Username.value==""){
			 alert("Please enter Username!");
			  return false;
		   }else if(document.frmLogin.Password.value==""){
			 alert("Please enter Password!");
			  return false;
		   }	 
		
	}else{
	  return true;
	}
		
	
	}