function ToggleOpslagKnap(dropDownList, knapID, feltID)
{
    var knap = document.getElementById(knapID);
    var felt = document.getElementById(feltID);
    var option = dropDownList.options[dropDownList.selectedIndex];
    if (option.title) 
    {
	    knap.style.display="inline-block";
    	felt.value = option.title;
    }
    else
    {
	    knap.style.display="none";
    	felt.value = "";
    }
}