multiple selection listbox problem urgent help req

Question

i have a query in asp net. in an application i have textbox and a multiselect listbox. the values which got selected in these two controls i need to pass them to two different parameter so that when they are used in sql query i can get the values of other columns also on the basis of these passed values on grid view on the same page. can anyone tell me how to achieve this in simple steps with eg m just a begginner and working on .net first time.