function checkForm(f){
	var length=f.elements.length;
	var results=new Array();
	var names=new Array();
	var k=0;
	var old_name="";
	for(var i=0;i<length;i++){
		var element=f.elements[i];
		var name=element.name;
		if(element.type=="radio"){
			if(name!=old_name){
				names[k]=name;
				k++;
				old_name=name;
				results[name]=false;
			}
			if(element.checked)results[name]=true;
		}
	}
	var final_result=true;
	var length1=names.length;
	for(i=0;i<length1;i++){
		if(results[names[i]]!=true){
			j=i+1;												
			alert("Please answer question "+j+" ("+names[i]+")");
			final_result=false;
		}
	}	
	return final_result;		
}