This is not a small answer, nor is there a single way of doing this. The basic structure is you have an HTML textbox that the user types search in and a button for them to click when they are done. When they click the button a javascript fires that posts the data to the server (this could be done through form post, XMLHTTP post to another ASP, etc.). Upon receiving the post the ASP page queries the database through the business layer (generally a
VB COM dll though you could do it directly through ASP in a small solution). The ASP then converts the return to HTML which is posted in a DIV tag. For more information you will need to POST a more specific question.
Yehuda