I am unable to launching R/3 Sale Order (VA01) in SAP CRM7.0 EHP1 ...

Hello,

I am unable to Launching R/3 Sales Order in CRM 7.0 Ehp1 via Transaction launcher it is asking user name and password, even I have been giving login credentials but it didn't work. And also I didn't get any exceptions or any Error. Please rectify this error.

Note: RFC, Logical system and URL of ITS settings are everything is fine.