Problem with combobox

Hi everyone,

I create one SSRS report and use four extended date types . (2 built in and I did 2 more). Build in are PurchId and InvoiceDate. I did OrderAccount and DeliveryDate. When adding them as parameters , they look different.

I want OrderAccont to be the same as PurchaseOrder. OrderAccount looks like field , want to look like combobox(PurchaseOrder).

I had this problem with dates. When I pressed the button on DeliveryDate , nothing was happening. I opened properties on extended datetype(DeliveryDate) and Extends field wrote TransDate and started to work. I think I have to set up OrderAccount.