Try this:
add a Catalog Client script (on the Catalog Item level) with the following:
function onLoad() {
//Type appropriate comment here, and begin script below
this.my_g_form = g_form;
}
And change your onLoad script to:
function onLoad() {
//Type appropriate comment here, and begin script below
if (parent.g_form) {
g_form.addInfoMessage("message");
}
else if (this.my_g_form) {
this.my_g_form.addInfoMessage("message");
}
}
