Conditional statement evaluating wrong [closed]

According to the program below, if donuts = 1 it will assign 0 to donuts, but if I run this it shows that 0 is assigned to donuts. Please tell me what I am over looking. Because how I see this code donuts should equal 12, because donuts should have fallen into the else:

#include <iostream> // Header file to enable console I/O
#include <string>   // Header file to enable string
#include <iomanip>  // enables maniplution of io strem
using namespace std;

// Begin main Function Definition
int main()
{
int donuts = 10;
if (donuts = 1)
{
    donuts = 0;
}
else
{
    donuts += 2;
}
cout<< donuts;
system("PAUSE");
return 0;

}
// End of main function