On Error statement

On Error { GoTo line | Resume Next | GoTo 0 }

Sets BlueZone Basic’s error-handling method and if applicable specifies the line label of the error-handling routine.

The line parameter refers to a label. That label must be present in the code or an error is generated.

Example

Sub Main
   On Error GoTo dude   ' Turn on error checking
   Dim x as object
   x.draw   ' Object not set
   jpe   ' Undefined function call
   print 1/0   ' Division by zero
   Err.Raise 6   ' Generate an "Overflow" error
   MsgBox "Back"
   MsgBox "Jack"
   Exit Sub
 
dude:
   On Error Resume Next   ' turn off error checking
   MsgBox "HELLO"
   Print Err.Number, Err.Description
   Resume Next
   MsgBox "Should not get here!"
   MsgBox "What?"
   On Error Goto 0   ' turn on error checking
End Sub

Errors can be raised with the syntax

Err.Raise x

The list below shows the corresponding descriptions for the defined values of x.

5:  "Invalid procedure call";
6:  "Overflow";
7:  "Out of memory";
9:  "Subscript out of range";
10: "Array is fixed or temporarily locked";
11: "Division by zero";
13: "Type mismatch";
14: "Out of string space";
16: "Expression too complex";
17: "Can't perform requested operation";
18: "User interrupt occurred";
20: "Resume without error";
28: "Out of stack space";
35: "Sub, Function, or Property not defined";
47: "Too many DLL application clients";
48: "Error in loading DLL";
49: "Bad DLL calling convention";
51: "Internal error";
52: "Bad file name or number";
53: "File not found";
54: "Bad file mode";
55: "File already open";
57: "Device I/O error";
58: "File already exists";
59: "Bad record length";
60: "Disk full";
62: "Input past end of file";
63: "Bad record number";
67: "Too many files";
68: "Device unavailable";
70: "Permission denied";
71: "Disk not ready";
74: "Can't rename with different drive";
75: "Path/File access error";
76: "Path not found";
91: "Object variable or With block variable not set";
92: "For loop not initialized";
93: "Invalid pattern string";
94: "Invalid use of Null";
 
// OLE Automation Messages
429: "OLE Automation server cannot create object";
430: "Class doesn't support OLE Automation";
432: "File name or class name not found during OLE Automation operation";
438: "Object doesn't support this property or method";
440: "OLE Automation error";
443: "OLE Automation object does not have a default value";
445: "Object doesn't support this action";
446: "Object doesn't support named arguments";
447: "Object doesn't support current local setting";
448: "Named argument not found";
449: "Argument not optional";
450: "Wrong number of arguments";
451: "Object not a collection";
 
// Miscellaneous Messages
444: "Method not applicable in this context";
452: "Invalid ordinal";
453: "Specified DLL function not found";
457: "Duplicate Key";
460: "Invalid Clipboard format";
461: "Specified format doesn't match format of data";
480: "Can't create AutoRedraw image";
481: "Invalid picture";
482: "Printer error";
483: "Printer driver does not supported specified property";
484: "Problem getting printer information from from the system.";
 
// Make sure the printer is setp up correctly.
485: "invalid picture type";
520: "Can't empty Clipboard";
521: "Can't open Clipboard";