function validate_formate(length){
	count = 0;
	for(i=0; i<length; i++){
		if(document.getElementById("format_"+i).checked == false){
			count = count + 1;
		}
	}
	if(count == length){
		alert("You have to select atleast one format");
		return false;
	}else{
		return true;	
	}
	return false;
}