TAG * swf_InsertTag(TAG * after,U16 id); // updates frames, if necessary
TAG * swf_InsertTagBefore(SWF*swf, TAG * before,U16 id); // like InsertTag, but insert tag before argument
-int swf_DeleteTag(TAG * t);
+TAG * swf_DeleteTag(SWF*swf, TAG * t);
void swf_ClearTag(TAG * t); //frees tag data
void swf_ResetTag(TAG*tag, U16 id); //set's tag position and length to 0, without freeing it