javascript - Drop down menu not work -

i'm developing easy web application, , i'm using 2 js libraries: dat.gui , three.js.

my problem drop down menu locked. can't open it.

// gui initialization (dat.gui) function initgui() {      var options = function() {         this.tenda = 'bar';     };      config = new options();     var gui = new dat.gui();     var subgui = gui.addfolder('setting');     subgui.open();      // callbacks     subgui.add( config, 'tenda', ['bar', 'pie', 'area']).         onchange(             function() {                 if (config.tenda === 'bar') { ... }                 else if (config.tenda === 'pie') { ... }                 else if (config.tenda === 'area') { ... }             }         ); }; 

reading on web, seems known issue, in examples, see drop down menus working well. i'm new js, , thought "maybe there scoping issue", put initialization process inside function work. problem remains.

i'm working on ubuntu/chrome , ubuntu/firefox. check entire code here, use check boxes instead of drop down menu.

i face same problem. in code, listen mouse click event. , callback function that:

function ondocumentmousedown( event ) {     event.preventdefault();      ... //other code } 

i found out problem "event.preventdefault();", prevent clicking on drop down list, commenting it, problems solved. can check other functions related mouse click event.