jQuery count number of added table rows

I am hoping someone can help me discover the error in my code. What I am trying to do is simply count the number of table rows that were added to the table by the end user and if the table rows is not equal to 2 an alert box will pop up.

This is my html code:

<table width="100%" border="0" cellspacing="0" cellpadding="0" id="details">
<tr>
<td colspan="7"><input name="addRow" type="button" class="add" value="Click Here to Add" id="addRow">
</td>
</tr>
<tr>
<td><input name="deleteRowButton" type="button" class="deleteRowButton" value="-" id="deleteRowButton" style="margin-top:15px;">
</td>
<td width="" align="left">
<select class="section" name="section" style="margin-top:15px;">
<option value="select">Select</option>
</select>
</td>
<td width="" align="left">    
<select>    </select>
</td>
<td width="" align="left">                
<select>   </select>
</td>
<td width="" align="left">                
<select>    </select>
</td>
<td width="" align="left">
<select>     </select>
<input type="text" value="" class="text" name="text" style="width: 100px;" />
</td>
<td width="" align="left">
<input type="text" /></td>
</tr>
</table>

And here are the add/delete functions:

    $("#addRow").live("click", function() {

        var row = $('#details tbody>tr:last').clone(true);
        context = $(this).parents("table").filter("#area");开发者_如何学Python 
        $("td input:text", row).val("");
        $("select option:selected", row).attr("selected", false);
        $("#details", context).append(row);
    });




$('.deleteRowButton').click(DeleteRow); 
       var rowCount = $('#details tr').length;         
       function DeleteRow()     {     
       if (rowCount == 2){
           alert($("#details tr").length);         
       } else {     
        $(this).parents('tr').first().remove();      
       } 
       }

Can anyone point out the problem to me?

the line where you count the rows (var rowCount = $('#details tr').length) should be inside the DeleteRow() function.

should it be:

if (rowCount != 2){ alert($("#details tr").length);
} else {
$(this).parents('tr').first().remove();
}

?