APIG error codes    

  5001    ; window pointer not valid
  5002    ; screen pointer not valid
  5003    ; gadget pointer not valid
  5004    ; requester pointer not valid
  5005    ; intuitext pointer not valid
  5006    ; menu pointer not valid
  5007    ; menuitem pointer not valid
  5008    ; subitem pointer not valid
  5009    ; iff pointer not valid 
  5010    ; expected non-null pointer
  5011    ; expected non-zero numeric
  5012    ; could not open iff.library
  5013    ; no console attached to window
  5014    ; invalid size specified in getvalue/setvalue
  5015    ; invalid owner specified for menu/item/subitem
  5016    ; could not load font 
  5017    ; could not load iff
  5018    ; border points  > 127 or thick > 25
  5019    ; invalid "link to" pointer
  5080    ; screenopen failed
  5081    ; attempt to closescreen with a window open
  5090    ; port not found
  5095    ; memory allocation failure
  5098    ; attempt to access low mem
  5099    ; task creation failure
  5200    ; not using dos v37 2.04
  5201    ; not a asl file requester pointer
  5202    ; asl file allocation failed
  5203    ; GadTool gadget creation failure
  5204    ; boopsi class object pointer invalid