compare database value

Question

hi friends

i have 5 textboxes(empid,date,intime,outtime,workingtime) and submittbutton

now i enter some integer value in the textboxes

now my query is

empid,date is already entered in database.i dont want enter same empid,date

how can i compared parricular empid,date exist or not.if that empid,date exists it will show error


thanks in advance

saravanan