>I have a table composed of four field
>field 1 Student Name
>Field 2 Mathematic, Chemistry ,Biology
>Field 3 Physic Mathematics Economic
>Field 4 Biology chemistry Mathematic
IMO, this reflects a bad database design. You should have each subject in a separate record (this might require a separate table) - this will allow you to filter on subject, and have a variable number of subjects. See my article on table normalization:
http://www.levelextreme.com/Magazine/August2002/Page7.asp.
A change in design will help you avoid or solve LOTS of problems.
HTH, Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)