Please use a password instead of textbox, this makes the password secure, and not readable to the user...
I know, this makes you get a char[] instead of a string, but this is much more secure, i do hope you don't send the password trough in plain text? Ifso, this would be very bad...
Also, you could store the password as a SHA-1 String or something (possible to convert char[] to SHA-1, there are functions for it), and this SHA-1 should be send to server then!