You can find the definition of errChk in toolbox.h. errChk is a convenient macro that allows you to structure your error handling code as an exception- handler -- something like a C-language version of the C++ try-catch block.
Normally errChk is used around a function call that can return an error. The macro evaluates the return value of the function, and if it's non-zero it jumps to the code following an "Error:" label that you should define at the bottom of the function. Normally the code after that error label will clean up any resources created by the function, and then propagate the error up to the calling function.
The use of errChk(1) is not very common, but is intended to always force the execution to jump to the Error handler with an error value of 1.
Luis
