Reading some recent posts about IDL limits, here is a list off the top of my head. Please post any additions or corrections. IDL limits: local variables <236 (?) common block variables <64 pro/function parameters <64 CALL_EXTERNAL parameters <64 structure tags <126 (?) variables (v3.5.1 & earlier) <16 characters pro/func names (?) -Bob mallozzi@ssl.msfc.nasa.gov