export to excel when multiple selections are made in a multibox

[#1]

Hi

I have created a report in which the various parameters of the reports can be selected by a multibox. In the multibox there are 5 parameters market,product,price,location,code. whenevr a user selects only one value from the parameter the export to excel buttons works and data for the selection comes into the excel.

But when user selects two values from any paramter at the same time then the export to excel button doesnt work and it doesnt show selection made inot multibox in the excel.

How can i solve this problem????