Sliding window leaking 2003 Duetto

Happy new year to all just returned from Hawes where it was very wet yesterday, we sprang a leak it is coming from the sliding window on the right hand side I think it is coming where the window is glued to the body at the top we had to put a pan an the back of the sofa to catch the water. Any one had one of these windows out and what are they stuck in with

any info please

Brian

Had a better look today the fiber glass frame is cracked which fits around the window i put some sealer in as a temporary fix. Any one had this before and are parts available 

any help please

Brian