hello all,

I have two report , first is main report which is matrix and have one parameter User_ids which is multi value selection

and my second report is basic chart of user_wise performance 

Now, my main report (matrix ) works fine for Multiple selection of users and i have putted one textbox on main report chart which has action properties set for chart report 

when user click on chart button it must goes to chart with user selected in main report 

Now , i have used expression for parameter to send it like ..

=join(parameter!user_id!value,",") which pass selected value to chart 

and when i am selecting single user it passing that value to chart parameter list but , when it is more than one user it errors with conversion failed when converting the nvarchar value '121,128' to data type int.

but my chart also works when passing 121,128 in user parameter in preview of report .

please , tell me why this is happening ?