function checkFreeItems() {

	var result = "";

	if (sFieldsToCheck!="") {

        var fields = sFieldsToCheck.split(',');
        
        for (i=0;i<fields.length;i++) {
            sPrefixToCheck = fields[i].substring(2,fields[i].indexOf("p"));
            
            if (document.getElementById("divFreeItem"+sPrefixToCheck).style.display!="none"){
            
                if (document.getElementById(fields[i]).value=="0") {
                    alert("Please select free item.");             
                    document.getElementById(fields[i]+"Level_1").focus();
                    return "ERROR";
                }
                else {
                    if (result!="") {
                        result+=",";
                    }              
                    result += document.getElementById(fields[i]).value;
                }
            }                   
        }
	}

	if (sNoAttributeProducts!="")
	{
		if(result!="") {
			result+=","
		}
		
		result+=sNoAttributeProducts
	}

	return result;            
}