Class void function not accepting parameter

I have a class vendor created. I have a public function call loadmachine. Example: void Vendor::loadmachine(); I want to read in a file to Loadmachine in my main program
Example:
sodaMachine.loadmachine(ifstream& fileName).
{
   inFile.open;
}
I am getting error c2061 syntax error identifier ifstream in my vendorType.h file. The function reads void Vendor::loadmachine().  
As you can probably see, I am new to programming. I have tried just place the items from the file into the function. sodaMachine.loadmachine(cans, bottles) neither functions work.  Any assistance would be appreciated.