Filter Textbox Value

can you help me guys..

i just want to put an expression on my textbox that will count my category "Staff" and "Labor" from Employees

in textbox1 it has a value Staff and textbox2 is blank and i want to put a expression on it.

the expression should be like this

=IIF(ReportItems!Textbox1.Value = Fields.Category.Value),Count(Fields.Employee.Value--CountOfStaff),Count(Fields.Employee.Value--CountOfLabor))

RESULT:

textbox.Staff  |   20  

texbox.Labor  |   10

Thanks in advance