title: loop inside another one from different sheets
body: <p>I have a problem with my loop.</p>
  
  <p>The task:</p>
  
  <p>look at the first row &amp; column (1,1) of sheet A, if it's not empty, look at first row &amp; column of sheet B, if it's not empty either, sum.</p>
  
  <p>Look at second row (first column) of sheet B, if it's not empty sum with sheet A (1,1) and on... </p>
  
  <p>If sheet B (x,1) is empty, go to sheet A (2,1) and do the same process: A(2,1)+B(1,1) , A(2,1)+B(2,1) , A(2,1)+B(3,1)</p>
  
  <p>If A(x,1) is empty, then exit the macro.</p>