function showhide(id){
if (document.getElementById){
obj = document.getElementById(id);
if (obj.style.display == "none"){
obj.style.display = "";
} else {
obj.style.display = "none";
}
}
} 


function removeAllOptions(selectbox)
{
    var i;
    for(i=selectbox.options.length-1;i>=0;i--)
    {
        //selectbox.options.remove(i);
        selectbox.remove(i);
    }
}

function move_all_Option(selectbox)
{
    for(i=document.drop_list.Category.options.length-1;i>=0;i--)	
    {
        var Category=document.drop_list.Category;
        addOption(document.drop_list.SubCat, document.drop_list.Category[i].value, document.drop_list.Category[i].value);
    }
    removeAllOptions(document.drop_list.Category);
}