How do I set the cursor to a particular position in the string value of a text INPUT field in Internet Explorer?

I already have this working in Firefox, Safari and Chrome.

I would like to be able to programmatically set the position of the text cursor within an INPUT field in Internet Explorer.

I looked this topic up on various websites and generally found the same tec开发者_运维问答hnique:

var el = document.getElementById("myTextField");
var pos = 6;

if (document.selection) {
    el.focus();
    var selection = document.selection.createRange();
    selection.moveStart("character", -el.value.length);
    selection.moveStart("character", pos);
    selection.moveEnd("character", 0);
    selection.select();
}

The problem is that when I try to do this the cursor always goes to the end of the value regardless of what position I provide.

Did I misunderstand the technique people have been using? Did I miss something somewhere? It's a little bit frustrating, but of course that's the nature of web development with these different browsers.

Thanks in advance for any help.

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The following code is working for me in IE 9

<script type="text/javascript">
    var input = document.getElementById("myInput");
    input.selectionStart = 2;
    input.selectionEnd = 5;
</script>

Here is the code that I'm using for IE 6

      input.select();
        var sel = document.selection.createRange();
        sel.collapse();
        sel.moveStart('character', this.SelectionStart);
        sel.collapse();
        sel.moveEnd('character', this.SelectionEnd - this.SelectionStart);
        sel.select();