Didn't check your script but try this:
PHP Code:
//#CLIENTSIDE
if (created) {
removetiledefs;
addTileDef imagename, levelprefix, 1;
}
For online usage, use this (like in a weapon):
PHP Code:
//#CLIENTSIDE
function onCreated() {
removetiledefs();
addTileDef("imagename", "levelprefix", 1);
}