function check_empty()
	{

		if(document.getElementById("ctl00_ContentPlaceHolder1_left_ddArrive").selectedIndex==0)
		{
			alert('Please enter a check in day');
			return false
		}
        
        if(document.getElementById("ctl00_ContentPlaceHolder1_left_mmArrive").selectedIndex==0)
		{
			alert('Please enter a check in date');
			return false
		}

        if(document.getElementById("ctl00_ContentPlaceHolder1_left_nights").selectedIndex==0)
		{
			alert('Please enter the number of nights required');
			return false
		}

        if(document.getElementById("ctl00_ContentPlaceHolder1_left_guests").selectedIndex==0)
		{
			alert('Please enter the number of guests');
			return false
		}
        if(document.getElementById("ctl00_ContentPlaceHolder1_left_rooms").selectedIndex==0)
		{
			alert('Please enter the number of rooms');
			return false
		}
		
			return true
	}
	
	
	function clear(objSelect){

     for (var i = (objSelect.options.length-1); i >= 0; i--){
         objSelect.options[i]=null;
     }
     //objSelect.options[0]=new Option('Please select', '');
	}
	function addOption(selectbox,text,value )
	{
		var optn = document.createElement("OPTION");
		optn.text = text;
		optn.value = value;
		selectbox.options.add(optn);
	}
	
	
	function addOption_list(aaa){
		clear(document.frm.course_date);
		
		if(aaa=="Course1")
			var month = new Array("01/03/08","01/04/08","01/05/08");
		else if(aaa=="Course2")
			var month = new Array("15/03/08","15/04/08","15/05/08");
		else
			var month = new Array("");

		for (var i=0; i < month.length;++i)
		{
			addOption(document.frm.course_date, month[i], month[i]);
		}
	}