Question : Error in Regex expression...

What's wrong with the one line of code below?  The field contains a number, possibly followed by non-numeric characters.  I am trying to eliminate everything except the first numeric characters.

Visual Studio IDE says I have "invalid arguments".  What am I doing wrong?

1:	NbrOfPages = Regex.Replace(NbrOfPages,@"^\d+");

Answer : Error in Regex expression...

yes it should do but what you are trying to exactly do with your regex?
are you trying to remove everything from the string except the digits?
if so then try this:
 NbrOfPages = Regex.Replace(NbrOfPages, @"[^\d]", "");