Wrapping up, removed ENDIF statement (there was no IF to begin with).
Added 0 to Exit statement.
Removed empty lines.
 Code:
; *****************Section 1***********************
; Default Logon Script for ASA CO
; 
; *****************Section 2***********************
; Clear Screen
CLS
;
Color g+/n
Big ; Display in BIG character mode
at (2,10) "ASA"
;
sleep 2 ; Wait for 2 secs
;
; *****************Section 3***********************
;
CLS
;
at (12,22) "Please Wait For Logon script Execution"
at (13,22) "Progress"
;
;
; *****************Section 4***********************
;
; Map Drives to Server "
;
USE H: "\\servername\foldername"
;
at (13,32) ".."
;
sleep 1 ; Wait for 1 sec
;
EXIT 0