/*************************************

js_is_empty(val)
js_is_number(val)
js_chk_number(obj)
is_is_semail(str)
js_change_obj_color(jObj, xNormal)

*************************************/

function js_is_empty(obj){
  var valstr = obj.value + "";

  if (valstr.length == 0) 
  {
  	js_change_obj_color(obj, 0)
	alert("黃色欄位必須填入");
  	return true;
	
  }
  else
  {
  	js_change_obj_color(obj, 1)
	return false;
	
  }
}

function js_is_email_empty(obj){
  var valstr = obj.value + "";

  if (valstr.length == 0) 
  {
  	js_change_obj_color(obj, 0)
	alert("Please enter your e-mail address in order to stay connected.");
  	return true;
	
  }
  else
  {
  	js_change_obj_color(obj, 1)
	return false;
	
  }
}


function js_chk_number(obj){
	
	if (obj.value != ''){
		if (isNaN(obj.value)){	
			//obj.focus();
			js_change_obj_color(obj, 0)
			alert("黃色欄位必須為數字");
			obj.value = '0';
			
			
			return false;
		}
			return true;
		
	}

}


function is_email(obj) {
	
//	return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);

	s = obj.value

	var re = "^[A-Za-z0-9](([_\.\-]?[a-zA-Z0-9]+)*)@([A-Za-z0-9]+)(([\.\-]?[a-zA-Z0-9]+)*)\.([A-Za-z]{2,})$";
	
	if(s.match(re)){
		js_change_obj_color(obj, 1)
		return true;
		
	}else{
		js_change_obj_color(obj, 0)
//		alert("電郵地址不正確");
		alert("The e-email address does not appear to be valid, please confirm and try again.");
		return false;
		
	}

}


function js_change_obj_color(jObj, xNormal){
	
	if (xNormal)
	{
		jObj.style.backgroundColor = '#FFFFFF';
	}
	else
	{

		jObj.style.backgroundColor = '#FFFFCC';
		try{
				jObj.focus();
				
		}
		catch(e){
		
		}
		
	}

}