Excel table parsing

This code parses output of Excel-document and put it to array.

function ParseExcelTable (pageNum) 
{
 document = Document.ObjectModel ();
 documentPage = document.GetPage (pageNum);
 textObjects = documentPage.GetTextObjects ();
 
 // result parsed table
 var table = new Array ();
 var row_id = new Array ();

 var col_id = new Array ();
   
 // looking through all the text objects
 var row = 0, column = 0;
 for (key = 0; key < textObjects.length; ++key) 
 {
  textObject = textObjects [key];
  base = textObject.Attribute ("base");
  left = textObject.Attribute ("left");
  
  // checking whether the text object is the first one in a row
  if (left == textObjects [0].Attribute ("left")) 
  {
   try { row_id [base] }
   catch (er) { row_id [base] = row++; }
   if (row_id [base] == undefined)
   row_id [base] = row++;
  }

  // checking whether the text object is the first one in a column
  if (base == textObjects [0].Attribute ("base")) 
  {
   try { col_id [left] }
   catch (er) { col_id [left] = column++; }
   if (col_id [left] == undefined)

   col_id [left] = column++;
  }
 }
 
 // result table initialization with undefined values
 for (r in row_id) 
 {
  table [row_id [r]] = new Array ();
  for (c in col_id)
   table [row_id [r]] [col_id [c]] = undefined;
 }

 // filling the table
 for (key = 0; key < textObjects.length; key++) 
 {
  textObject = textObjects [key];
  base = textObject.Attribute ("base");
  left = textObject.Attribute ("left");
  text = textObject.Attribute ("value");
  
  try { row_id [base] }
  catch (er) 
  {
   print ("unexpected y at: '" + base + "' '" + left + "' " + text);
   continue;
  }
  try { col_id [left] }
  catch (er) 
  {
   print("unexpected x at '" + base + "' '" + left + "' " + text);
   continue;
  }
  table [row_id [base]] [col_id [left]] = text;
 }
 print ("Excel table has been successfully parsed.");
 return table;
}

Sample of use:

var table = ParseExcelTable( 0 );
print( table[ 2 ][ 2 ] );