Try this which I got from code project, its a great way to do a query from a form with multiple parameters

Create Procedure sp_EmployeeSelect_Coalesce

@EmployeeName NVarchar(100),

@Department NVarchar(50),

@Designation NVarchar(50),

@StartDate DateTime,

@EndDate DateTime,

@Salary Decimal(10,2)

AS

Set NoCount ON

Select * From tblEmployees

where EmployeeName = Coalesce(@EmployeeName, EmployeeName) AND

Department = Coalesce(@Department, Department ) AND

Designation = Coalesce(@Designation, Designation) AND

JoiningDate >= Coalesce(@StartDate, JoiningDate) AND

JoiningDate <= Coalesce(@EndDate, JoiningDate) AND

Salary >= Coalesce(@Salary, Salary)

If @@ERROR <> 0 GoTo ErrorHandler

Set NoCount OFF

Return(0)

ErrorHandler:

Return(@@ERROR)

GO