function set_value_difficulty() {
	var c_value = "";
	for (var i=0; i < document.questionForm.add_value.length; i++)
	   {
		  if (document.questionForm.add_value[i].checked) {
			c_value = c_value + document.questionForm.add_value[i].value + ";";
		  }
	   }
	document.questionForm.steps.value = c_value;
}