function _getPopButtonPosition(){
        var htBlockInfo = _getBlockData();
        var htElements = _getElementsByOffsetOptions(htBlockInfo);

        var nColumnWidth = 7;
        var nLineHeight = 1.5;
        var nColumn = htBlockInfo.bIsReversed ? htBlockInfo.nStartColumn : htBlockInfo.nEndColumn;
        var welLine = htBlockInfo.bIsReversed ? htElements.welStartLine : htElements.welEndLine;

        var welCode = welLine.find("td.code");
        var htCodeOffset = welCode.position();
        var nMaxLeft = htElement.welContainer.width() - (htElement.welPopButtonOnBlock.width() * 2);

        return {
            "top" : htCodeOffset.top - (welCode.height() * nLineHeight),
            "left": Math.min(htCodeOffset.left + (nColumn * nColumnWidth), nMaxLeft)
        };
    }
Returns proper position for welPopButtonOnBlock.
Calculate top, left offset position by finding last line of selection block.

@returns {Hash Table} {top: number, left: number}
@private