Queries :: Update Query With Form Field

i have two tables one is "empdata" and other is "consolidate data".In consolidate data ,i have all personal and salary data for one year of each employee but i update some employee data in empdata now i want to update each employee updated data to update in consolidate data. i want to do it with update query which run with form,is form i want create 2 combo box, 1st is employee name and 2nd is field name(which to be updated i.e. Date of birth)now i have one text box (in which i enter the value for update in employee data i.e.04/05/1976(date of birth)).how can i link this form to my update query as

1st combo box value is equal to creteria,
2nd combo box is equal to field in consolidate

and text box is value for updation...