Prevent Multiple Selections of Same Value

Question

I am working on a project where I have a form that will have multiple \'select\' inputs, all with the same set of options. I would like to use jquery to disable/hide an opt

Answer 1

To hide them, use the following approach (since IE bug prevents using CSS "display" property setting to "none" on an OPTION):

-Store the original list of options in an array

-Have a function to build the select #x from an array, slipping previously selected items

-Assign an onchange handler for all selects which loops through all later selects and calls this function.

var option_value_order = {'volvo', 'saab', 'mercedes'};
var option_display_strings = new Array();
option_display_strings['volvo'] = 'Volvo'; 
//...

// Assume each of the selects' ID value is "select_1", "select_2" instead of "1", "2"
function redraw(selectNum) {
    var selectId = "select_" + selectNum;
    var s = document.getElementById(selectId);
    s.options.length = 0; // empty out
    var next = 0;
    for (var i = 0; i < option_value_order.length; i++) { 
        var skip = 0;
        for (var select_index = 0; select_index < selectNum; select_index++) {
            if (document.getElementById("select_"+select_index).selected == i)
                skip = 1;
            if (skip == 0) {
                var o = option_value_order[i];
                s.options[next] = o;
                // Don't recall how to set value different from option display, 
                // using option_display_strings[o] 
                next++;
            }
        }
    }
}

var total_selects = 2;

function change_later_selects(s) {
    var select_num = find_number(s.id); "this returns number 2 for "select_2" - homework
    for (var i = select_num + 1; i <= total_selects; i++) {
        redraw(i);
    }
}

And then the HTML

  Volvo
  Saab
  Mercedes