title: check if a cell of table contains a certain form
body: <p>I want to check if a specific cell in a table contains a specific form using JavaScript.</p>
  
  <p>Here is what I have done:</p>
  
  <pre><code>for(var i = 1; i &gt;= mainTable.tBodies[0].rows[2].length; i++)
  {
      if(mainTable.tBodies[0].rows[2].cells[i].elements[0] == document.getElementById("my_form"))
      {
          var cellIndex = i;
          alert("cell" + i + " contains the form");
          break;
      }
  }
  </code></pre>
  
  <p><code>"my_form"</code> is actually inside cell number <code>1</code>, but the if-statement is always false despite it should be true at <code>i = 1</code>. How can I achieve this in JavaScript?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>Here is the whole code:</p>
  
  <pre><code>&lt;HEAD&gt;
  &lt;SCRIPT LANGUAGE="JavaScript"&gt;
  &lt;!-- Begin
  
  //var mainTable = document.getElementById("mainTable");
  var index_Skill = 1;
  var index_Speed = 1;
  var index_Age = 1;
  var index_Strength = 1;
  var index_Height = 1;
  
  function moveUp(theForm)
  {
      if(theForm == "form_Skill")
      {
          if(index_Skill == 1)
          {
              // get the max index of the table
              var newIndex = Math.max(++index_Skill, ++index_Speed, ++index_Age, ++index_Strength, ++index_Height);
  
              // insert a new row
              var newRow = mainTable.tBodies[0].insertRow(newIndex);
  
              // shift the rows one level down
              for(var i = newIndex; i &gt; 1; i--)
              {
                  mainTable.tBodies[0].moveRow(i - 1, i);
              }
  
              // delete (skill) from the old index
              var cellIndex;
              for(var i = 1; i &gt;= mainTable.tBodies[0].rows[2].length; i++)
              {
                  if(mainTable.tBodies[0].rows[2].cells[i].elements[0] == document.getElementById("form_Skill"))
                  {
                      cellIndex = i;
                      alert(i);
                      break;
                  }
              }
              for(var i = cellIndex; i &gt;= mainTable.tBodies[0].rows[2].length; i++)
              {
                  mainTable.tBodies[0].rows[2].cells[i].innerHTML = mainTable.tBodies[0].rows[2].cells[i+1].innerHTML;
              }
              //mainTable.tBodies[0].rows[2].cells[mainTable.tBodies[0].rows[2].length].innerHTML = "";
  
              // add (skill) to the new index
              var newCell = mainTable.tBodies[0].rows[1].insertCell(0);
              newCell.innerHTML = 1;
              newCell.setAttribute("align", "center");
              var newCell = mainTable.tBodies[0].rows[1].insertCell(1);
              var obj = document.getElementById(theForm).cloneNode(true);
              newCell.appendChild(obj);
  
              // fixes the id's
              for(var i = 1; i &lt;= newIndex; i++)
              {
                  mainTable.tBodies[0].rows[i].cells[0].innerHTML = i;
                  mainTable.tBodies[0].rows[i].cells[0].setAttribute("align", "center");
              }
  
          }
      }
  }
  
  
  function moveDown(theForm)
  {
  
  }
  
  
  //  End --&gt;
  &lt;/script&gt;
  &lt;/HEAD&gt;
  </code></pre>
  
  
  
  <pre><code>&lt;BODY&gt;
  
      &lt;table id="mainTable" name="mainTable" border="1"&gt;
  
          &lt;tr&gt;
              &lt;th&gt;Rank
              &lt;/th&gt;
              &lt;th colspan="5"&gt;
                  &lt;p align="center"&gt;The Criteria
              &lt;/th&gt;
          &lt;/tr&gt;
          &lt;tr&gt;
              &lt;td&gt;
                  &lt;p align="center"&gt;1
              &lt;/td&gt;
  
              &lt;td&gt;
                  &lt;form name="form_Skill" method="post" style="margin: 0; text-align: center;"&gt; 
                      &lt;input type="button" name="Up1" value="Up" onclick="moveUp('form_Skill');"&gt; Skill
                      &lt;input type="button" name="Down1" value="Down" onclick="moveDown('form_Skill');"&gt;
                  &lt;/form&gt;
              &lt;/td&gt;
  
              &lt;td&gt;
                  &lt;form name="form_Speed" method="post" style="margin: 0; text-align: center;"&gt; 
                      &lt;input type="button" name="Up2" value="Up" onclick="moveUp('form_Speed');"&gt; Speed
                      &lt;input type="button" name="Down2" value="Down" onclick="moveDown('form_Speed');"&gt;
                  &lt;/form&gt;
              &lt;/td&gt;
  
              &lt;td&gt;
                  &lt;form name="form_Age" method="post" style="margin: 0; text-align: center;"&gt; 
                      &lt;input type="button" name="Up3" value="Up" onclick="moveUp('form_Age');"&gt; Age
                      &lt;input type="button" name="Down3" value="Down" onclick="moveDown('form_Age');"&gt;
                  &lt;/form&gt;
              &lt;/td&gt;
  
              &lt;td&gt;
                  &lt;form name="form_Strength" method="post" style="margin: 0; text-align: center;"&gt; 
                      &lt;input type="button" name="Up4" value="Up" onclick="moveUp('form_Strength');"&gt; Strength
                      &lt;input type="button" name="Down4" value="Down" onclick="moveDown('form_Strength');"&gt;
                  &lt;/form&gt;
              &lt;/td&gt;
  
              &lt;td&gt;
                  &lt;form name="form_Height" method="post" style="margin: 0; text-align: center;"&gt; 
                      &lt;input type="button" name="Up5" value="Up" onclick="moveUp('form_Height');"&gt; Height
                      &lt;input type="button" name="Down5" value="Down" onclick="moveDown('form_Height');"&gt;
                  &lt;/form&gt;
              &lt;/td&gt;
  
          &lt;/tr&gt; 
      &lt;/table&gt;
  &lt;/body&gt;
  </code></pre>