I had a strange problem with the loading mask.

My application has a chart and a grid page. From chart on a button click i am trying to load the grid page. Since the grid page takes a while to load i have put a loading mask. But the problem is when the loading mask is shown the chart legend is displayed on top of the mask and is clickable. Also the graph is put inside a tab panel and the tab button of the tab panel also comes on top of the loading mask.

Please find attached the screen shot. Any help on how this can be avoided is highly appreciated.