Get the max and min values

Question

i have a columns in database named highest. i have 2 textboxes(max,min) and 2 button(max, min) in asp.net web page. i want that when i click on max button it takes the highest values from that column in database and show it in max text box. when i click on min button it takes the minimum value to that column and show it in min text box. remember i am using asp.net web page.please tell me the solution.also code if possible