function runEffect(selectedEffect, prvek, rodic){
    //otevirany prvek napozicujeme
    var pos = $j("#" + rodic).position();
    var sirka_rodic = $j("#" + rodic).width();
    var sirka_elm = $j("#" + prvek).width();
    $j("#" + prvek).css({ position: "absolute", top: pos.top, left: pos.left - (sirka_elm/2) + (sirka_rodic/2) + 15 });

    //most effect types need no options passed by default
    var options = {};
    //check if it's scale, transfer, or size - they need options explicitly set
    if(selectedEffect == 'scale'){  options = {percent: 0}; }
    else if(selectedEffect == 'size'){ options = { to: {width: 200,height: 60} }; }

    //run the effect
    $j("#" + prvek).toggle(selectedEffect,options,350);
};