Hi There can anybody help !

Hi there what it is i have 3 travel databases Rail,Air and Sea which are all linked into my employee file , i need crystal to look at the payroll no. in the travel files (all 3 of them) and look for them in the employee file and if they are not in there for it to say "Invalid Payroll Number".

For Example (I know this example does not work but it might give you a better idea of what i mean)

If isnull ({Rail.Payroll No}),({Air.Payroll No}),({Sea.Payroll No}), Then
"Invalid Payroll Number" Else
{Rail.Payroll No},{Air.Payroll No},{Sea.Payroll No}

Hope this makes sense to some one out there, A BIG CHEERS TO ANYBODY WHO CAN help