c# - If else condition on dropdown list on MVC -

i have 2 dropdown list on web application. populated data of 2 dropdown comes database. contain same data.

what want if 1 of list selected on first dropdown, should not available on second dropdown anymore.

i have following razor syntax:

@html.dropdownlistfor(model => model.questions1, (selectlist)viewdata["questions"], "select>>", new { id = "questions1", name = "questions1"})  @html.dropdownlistfor(model => model.questions2, (selectlist)viewdata["questions"], "select>>", new { id = "questions2", name = "questions2"}) 

the questions came model retrieve database.

thanks in advance!

in order accomplish this, need store pool of options in javascript object. then, in 'onchange' event each drop-down, re-build options in other drop-down, excluding 1 chosen. here example using jquery:

// build javascript array of select names/values var options = new array(); $('#questions1 option').each(function() {     $this = $(this);     options.push({ name: $this.text(), value: $this.val() }); });  // create function re-building select minus chosen option var rebuildselect = function($seloption, $select) {     $previouslyselected = $select.find(':selected');     $select.empty();     (var = 0; < options.length; i++) {         var opt = options[i];         if (opt.value != $seloption.val()) {             if ($previouslyselected.val() == opt.value) {                 $select.append('<option value="' + opt.value + '" selected="selected">' + opt.name + '</option>');             }             else {                 $select.append('<option value="' + opt.value + '">' + opt.name + '</option>');             }         }     } }  // wire event handlers var $questions1 = $('#questions1'); var $questions2 = $('#questions2');  $questions1.change(function() {     rebuildselect($(this), $questions2); });  $questions2.change(function() {     rebuildselect($(this), $questions1); });  // go ahead , run function on each box remove default entries other box rebuildselect($questions1.find(':selected'), $questions2); rebuildselect($questions2.find(':selected'), $questions1); 

http://jsfiddle.net/n5k99/