Date Filter problem while using in Navigation-->Jump to URL

gdkve9

Dear Mibusonians,

I have got a strange problem while applying filters in Jump to URL expression of Navigation.

It works fine for the following expression:

="DynamicsNAV:////runreport?Report=50045&Filter=%22G/L Entry%22.%22Entry No.%22:0"+
"&Filter=Customer.%22No.%22:0"+
"&Filter=Vendor.%22No.%22:0"+
"&Filter=%22Bank Account%22.%22Date Filter%22:01-04-11..05-04-11"

But when I am trying to use a variable for filtering the Date Filter in the above expression as shown below:

="DynamicsNAV:////runreport?Report=50045&Filter=%22G/L Entry%22.%22Entry No.%22:0"+
"&Filter=Customer.%22No.%22:0"+
"&Filter=Vendor.%22No.%22:0"+
"&Filter=%22Bank Account%22.%22Date Filter%22:"+Fields!BankAccDateFilter.Value

where

Fields!BankAccDateFilter.Value = 01-04-11..05-04-11

It gives following error.
"The Filter String contains invalid parameters"

I would be very grateful if someone could suggest on exact reason on the above issue.

I am stuck here ](*,)

Awaiting on helpful suggestions :-k

Thanks everyone in advance...