Index: trunk/pswarp/src/pswarpArguments.c
===================================================================
--- trunk/pswarp/src/pswarpArguments.c	(revision 27096)
+++ trunk/pswarp/src/pswarpArguments.c	(revision 27227)
@@ -14,4 +14,16 @@
 # include <glob.h>
 
+
+static void usage (void) {
+    fprintf(stderr, "USAGE: pswarp [-file image(s)] [-list imagelist] [options] (output) (skycell)\n");
+    fprintf(stderr, "  options:\n");
+    fprintf(stderr, "    [-astrom astrom.cmp] : provide an alternative astrometry calibration\n");
+    fprintf(stderr, "    [-mask mask.fits] : provide a corresponding mask image\n");
+    fprintf(stderr, "    [-variance variance.fits] : provide a corresponding variance image\n");
+    psErrorStackPrint(stderr, "\n");
+    exit(PS_EXIT_CONFIG_ERROR);
+}
+
+
 pmConfig *pswarpArguments (int argc, char **argv) {
 
@@ -20,6 +32,5 @@
 
     if (argc == 1) {
-        psError(PSWARP_ERR_ARGUMENTS, true, "No arguments supplied");
-        return NULL;
+        usage();
     }
 
@@ -91,6 +102,5 @@
 
     if (argc != 3) {
-        psError(PSWARP_ERR_ARGUMENTS, true, "Incorrect arguments supplied");
-        return NULL;
+        usage();
     }