PRO: spd_ui_validate_file PURPOSE: Verifies file read/write permissions and file availability Inputs: filename:name of the file Outputs: statuscode: negative value indicates failure, 0 indicates success statusmsg: a message to be returned in the event of an error Keywords: write: validate for save $LastChangedBy: jimm $ $LastChangedDate: 2014-02-11 10:54:32 -0800 (Tue, 11 Feb 2014) $ $LastChangedRevision: 14326 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/spedas/gui/utilities/spd_ui_validate_file.pro $