[jQuery] $.get() I Explorer 7 "Error Message: Object doesn't support this property or method"

[Albertux]

well i comment my problem:

example code:

javascript code using jquery1.2.3
...
function estado()
 {
        $.get("estados.php",{"pais":$('#pais').val()}, function(data){
                        $('#estadodiv').html(data)
        });
 }
.....
html code:
......
<select id="pais" name="pais" OnChange="estado()">
<option value="1" >Mexico</option>
<option value="2" >Estados Unidos</option>
<option value="3" >Colombia</option>
<option value="4" >Espa&ntilde;a</option>
<option value="5" >Argentina</option>
<option value="6" >Peru</option>
<option value="7" >Venezuela</option>
</select>
<div id="estadodiv">
</div>
.....

On Firefox 2x works fine, but using iexplorer 7 y get this message
error: "Error Message: Object doesn't support this property or method"

i use firebug on firefox and debugbar on explorer 7 but i can't resolv
the problem, any can tellme something to help my problem

(sorry if my english is not fine)