I am having a problem with casting

Here is the code that is having the problem

int questions()
{
while(strchr(uresponse,"?")==0)
{
cout << "I cannot yet respond to questions.\n";

}
}

and the error I get is this:
passing `const char *' to argument 2 of `strchr(const char *, int)' lacks a cast

I was reading in the programmers bible about casting and I cant exactly figure this one out. Can anybody be so nice as to help?

You don't need a cast. Try -

strchr(uresponse,'?')

thank you very much, that worked fine. What is the difference in "?" and '?'? I have used quotations when searching for full words within a given phrase and that works fine.

One's a char literal , the others a string literal -

'?' == {'?'}
"?" == {'?','\0'}

...and because the compiler cannot implicitly convert a char* (the "?") into the int the function expects, but can convert a char (the '?') into an int since a char is essentially an integral type just like ints are.