Update alphamapping.html

Purpose: 
Allow usage of Latin characters on web-page. Prevent possible storage of dummy values in DB.


Approach: 
alphaMapping is a JSON object that contains a one to many mapping between normal English letters and possible Latin letters. On the on-blur event of the required text fields, the function alertUser() is called. The entered string is searched letter by letter for Latin characters that have English replacements (from alphaMapping object). A new string is constructed with the replaced English letters. After the mapping process, we check if the new string is the same as entered string. If yes, do nothing since no further user input is required. If no, it means letters from the input were replaced; ask the user if the new string is acceptable. If the user hits OK, replace the string in the input field with the new string, else do nothing.