Equal height per row (http://css-tricks.com/equal-height-blocks-in-rows/)

equalheight.js

function equalHeight(element) {
  var currentTallest = 0,
      currentRowStart = 0,
      rowDivs = new Array(),
      $el,
      topPosition = 0;

  $(element).each(function() {

    $el = $(this);
    topPostion = $el.position().top;
    
    if (currentRowStart != topPostion) {
      // we just came to a new row.  Set all the heights on the completed row
      for (currentDiv = 0 ; currentDiv < rowDivs.length ; currentDiv++) {
        rowDivs[currentDiv].height(currentTallest);
      }
      // set the variables for the new row
      rowDivs.length = 0; // empty the array
      currentRowStart = topPostion;
      currentTallest = $el.height();
      rowDivs.push($el);
    } else {
      // another div on the current row.  Add it to the list and check if it's taller
      rowDivs.push($el);
      currentTallest = (currentTallest < $el.height()) ? ($el.height()) : (currentTallest);
    }
    // do the last row
    for (currentDiv = 0 ; currentDiv < rowDivs.length ; currentDiv++) {
      rowDivs[currentDiv].height(currentTallest);
    }     
  });
}

There is a topPostion at in line 13 also.