Return Code	Significance
0	all ok

With the help of a message-trap function e.g. DataView system messages can be evaluated and replaced by individual messages

Prior to the message output the passed function is called with the following parameters:

• char *nam: message name [0 = direct output]
• char *str1: 1. additional string [0 = not assigned]
• char *str2: 2. additional string [0 = not assigned]
• char *str3: 3. additional string [0 = not assigned]

If the passed function returns a return code = 0, the default message is output. If the return code is different from zero, the default message is not output. In this case dal_mes_wri can be used to write an individual message into the message window.