seperating charts

hi all,

Is there a way in excel 2007 to create one graph that shows vol as a bar graph and the second as a line graph showing val but when the user clicks a button for vol it sbows the bar graph and if the val is clicked then the line graph is showing but not at the same time as i know you can change the graph to primary or secondary?

i could have two seperate graphs overlapping but how would i get the interaction between vol and val to work?

Any ideas or guidance would be greatly appreciated.

Thanks.