array / pointer error?

[Speedi3579]

Hello,

I am writing a program that uses my own function to reverse a string and print the reverse. I am experiencing an error that I just don't know why it is occuring. Here is the code block, and the error:

int main()
{
	char myString[] = "aBc123";
	char revString[80] = "1";
	char *ch;
	
	ch = ToUpperStr(myString);
	revString = ReverseStr(myString, revString); // error, left operand must be l-value
	printf("%s\n%s\n", myString, ch);

	return 1;
}

and for clarification, here is my ReverseStr() function code(Note: it currently doesn't reverse the string, I'm holding off on writing that part until I get this current little error fixed):

char* ReverseStr(char * str, char * reverseStr)
{
//	char *strStart = str;
	char *revStart = reverseStr;
	
	
	while (*str)
	{
		*reverseStr = *str;
		str++;
		reverseStr++;
	}
        reverseStr = revStart;
	return reverseStr;
}

Does anyone know why my function can't return the address properly to revString? Is there something I am missing here? I want my function to return the address of the modified string, and the function should be passed the address that I want to place the modified string at.

Thanks in advance for your help,
Alan.