Palindrome, problem with isalpha

I don't know if I am implementing isalpha() correctly and doing something else wrong or it's in the wrong place. Where I have the isalpha now, once I compile and run it, it say everything is palindrome, which is definitely not right. What am I doing wrong?

Thanks

Here is the palindrome function, I don't think I need to post the main because it was given by my professor and there is no need to change it. If you need it, just say so.

Code:

int is_palindrome(const char *message)
{
	
	int k = tolower(strlen(message) - 1);
	int j;
	
	for(j = 0; j <= k; j++)
	{
		if(isalpha(tolower(message[j]) != tolower(message[k]))) 
		{	
			return 0;
		}
      
	k--;
    
	}
	   
	return 1;
}

I can think of no valid purpose for isalpha to serve here. The result of != is always either 0 or 1, and neither of those are alphabetical characters in ASCII.

In other words: "My program is not functioning correctly. I am thinking it is the result of a function that has been widely in-use for almost three decades."

Does that about sum it up? Because that isn't even a question, buddy.