Fixed bugs: 
1. Moved search functionality from doGet method to doPost (in DispCalc).
2. Eliminated exception when search doesn't return anything.

Added Functionality:
1. Added helpful alert messages for searches that don't return anything.
2. Added feature that checks search input and disables search button if
input is invalid.

Removed Functionality:
1. Removed search form from "Results" page and replaced with button.