function objGet(x) {
	if (typeof x != 'string') return x;
	else if (Boolean(document.getElementById)) return document.getElementById(x);
	else if (Boolean(document.all)) return eval('document.all.'+x); //document.all[x];
	else if (Boolean(document.layers)) return document.layers[x];
	else return null;
}

function objSetStyle (obj,prop,val) {
	var o = objGet(obj);
	if (o && o.style) {
		eval ('o.style.'+prop+'="'+val+'"');
		return true;
		}
	else return false;
	}

function objShow (obj,on) {
	
	return objSetStyle(obj,'visibility',(on) ? 'visible':'hidden');
	}

function objDisplay (obj,on,type) {
	if (on && !type) type = 'block';
	return objSetStyle(obj,'display',(on) ? type:'none');
	}

function list(ob, itemPrefix)
{
	obC = objGet(ob);
	for (var i = 0; i < obC.options.length; i++)
	{
		objtoShow = objGet(itemPrefix+obC.options[i].value);
	    if (obC.options[i].selected)
	    {
	    	objDisplay(objtoShow, true, 'block');
	    }else
	    {
	    	objDisplay(objtoShow, false, 'none');
	    }
	}
}

// Ceske ekvivalenty funkci:

var objNajdi = objGet;
var objNastavStyl = objSetStyle;
var objZobraz = objShow;