deselect selected item from select box

I have a select box that is activated/deactivated by a check box selection, when the user deacivates the selectbox by unchecking the checkbox i want to clear any selections they have made, that is deselect the selected item so that there is no hightlighted item.
i have tried
obj.selectedIndex=false; // selects first item in list
obj.selectedIndex=0;      // selects first item in list
obj.selectedIndex=-1;    // selects first item in list

obj.options[obj.selectedIndex].selected=false; no results

sorry about the cheap points it's all i have left
LVL 25
James RodgersWeb Applications DeveloperAsked:
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knightEknightCommented:
that should work, but you may try this:

selObj.focus();
selObj.selectedIndex =- 1;
selObj.blur();

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knightEknightCommented:
... but I suspect something else is going on.  Can you show us the code you are using on the checkbox to deselect the item?
knightEknightCommented:
should be something like this:

<INPUT type="checkbox" name="mycb" onclick="if(!this.checked)this.form.nameOfTheSelect.selectedIndex=-1;" />
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VincentPugliaCommented:
this what you looking for?
<html><head>
<script>
function deSelect(selObj)
{
  selObj.options[0].selected = true;
  selObj.options[selObj.selectedIndex].selected = false
}

</script>
</head>
<body>
<form name='a'>
<input type="checkbox" onclick='if (!this.checked) deSelect(this.form.c)'>
<select name="c">
<option selected>Select something</option>
<option>1</option>
<option>1</option>
<option>1</option>
</select>
</form>
</body>
</html>
James RodgersWeb Applications DeveloperAuthor Commented:
this is my checkbox

<input type="checkbox" value="3" name="optChange3" onclick="if(this.checked)document.frmAddPosition.selEmpList.disabled=false; else {document.frmAddPosition.selEmpList.options[document.frmAddPosition.selEmpList.selectedIndex].selected=false; document.frmAddPosition.selEmpList.disabled=true;}">Edit position holder<br>
VincentPugliaCommented:
so? call the function & make the necessary changes
James RodgersWeb Applications DeveloperAuthor Commented:
Vincent,
tried your code with same results

first item in option list is selected and remains selected.

knightEknight

i am going to try your first answer to see if the focus, blur results in the solution i need

Thanks
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