var selectedEffect = $( "#effectTypes" ).val();
// Most effect types need no options passed by default
var options = {};
// some effects have required parameters
if ( selectedEffect === "scale" ) {
options = { percent: 50 };
} else if ( selectedEffect === "size" ) {
options = { to: { width: 280, height: 185 } };
}
// Run the effect
$( "#effect" ).show( selectedEffect, options, 500, callback );