Jquery disable the already selected value not working

i look up the already existed date value in other table. i would like to disable if it is already selected in this select field.

This is the code that i put in client events:
$(‘#ctrl-date_lookup’).on(‘change’, function(){
$(‘option’).prop(‘disabled’, false);
$(‘select’).each(function() {
var val = this.value;
$(‘select’).not(this).find(‘option’).filter(function() {
return this.value === val;
}).prop(‘disabled’, true);

Thank you. I just recently bought a license, which is why I’m new to the RADSystem,

What language and framework are you working on?