Hi Adil,
BTW the standard parameter for work item id is _WI_ID - the initial underscore is part of the name. There is no standard parameter WI_ID.
If this is not the problem then please provide more details, e.g.
a) Whether other work items are launching ok
b) Whether other work items that launch web dynpros are launching ok
c) What is in your SWFVISU entry
d) Whether your web dynpro uses a web dynpro configuration or not
Regards,
Jocelyn