iterator on for loop with multiple ending conditions

Hi,
I'm no expert in C++ and I've quite a while tracking down a problem
which I believe I am summarising here. If anybody can help me out I'd
be very grateful!
The following piece of code doesn't work as I expect:

        int testIndex=0;
        vector<int> testyVec;
        testyVec.push_back(1);
        testyVec.push_back(2);
        testyVec.push_back(3);
        testyVec.push_back(4);
        testyVec.push_back(5);

       typedef vector<int>::iterator vecIterator;
        vecIterator vi;

        for(vi=testyVec.begin(); testIndex<3, vi!=testyVec.end();
++vi)
        {
           cout<<"itr: testIndex is "<<testIndex<< " and testyVec item
is "<<(*vi)<<"\n";
           testIndex++;
       }

 I expect the for loop to end after 3 iterations due to one of the
 ending conditions "testIndex<3". It doesn't. It goes on until the
 second ending condition is reached. In fact if I switch the order of
 the ending conditions then it always ignores the first one. Am I
 using incorrect syntax... is there some bug ... or what am I missing?!
(I know I can do this by putting && between the two conditions but I
thought the other syntax was also correct?)
 Thank you!
 Jane

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