but, this is simple to implement in javascript.. you will not be able to
disable some options in a select box but will be able to deselect the other
selections or display a message if ALL is selected.
Following function would deselect all except first item in the list...
function Deselect()
{
var theDayElement = window.document.form1.cmbDay
var optionCounter;
for (optionCounter = 1; optionCounter < theDayElement.length;
optionCounter++)
{
theDayElement.options[optionCounter].selected=false;
}
}
This function would check if first option (ALL) is selected and call
deselect() to deselect all other options
function CheckValue()
{
if( window.document.form1.cmbDay.options[0].selected == true)
DeselectAll();
}
your Select tag would look like below
<SELECT NAME="cmbDay" ID="cmbDay" multiple onchange="CheckValue();">
Hope this helps....