//CheckBoxList must check
function RequiredFieldValidator_CheckBoxList(val)
{
	var bCheck=false;
	
	var oCheckBoxList=document.getElementById(val.controltovalidate);
	var oCheckBoxs=oCheckBoxList.getElementsByTagName("input");
	for(var i=0;i<oCheckBoxs.length;i++)
	{
		if(oCheckBoxs[i].type=="checkbox" && oCheckBoxs[i].checked)
		{
			bCheck=true;
			
			return bCheck;
		}
	}
	
	return bCheck;
}

//must one and only one button checked

function RequiredFieldValidator_RadioButtonList(val)
{
	var bCheck=false;
	
	var oRadioButtonList=document.getElementById(val.controltovalidate);
	var oRadioButtons=oRadioButtonList.getElementsByTagName("input");
	for(var i=0;i<oRadioButtons.length;i++)
	{
		if(oRadioButtons[i].type=="radio" && oRadioButtons[i].checked)
		{
			bCheck=true;
			
			return bCheck;
		}
	}
	
	return bCheck;
}

//DropDownList must at least select not null or empty value
function RequiredFieldValidator_DropDownList(val)
{
	var oSelect=document.getElementById(val.controltovalidate);
	//not item
	if(oSelect.options.length==0)
	{
		return false;
	}
	
	//not item is select
	if(oSelect.value=="")
	{
		return false;
	}
	
	return true;
}