JS: detect right click without jQuery (inline)

Question

I'm calling a function, that builds a table which includes several links.

I want to check if a link has been clicked with right or left mouse.

I tried to add the following part to the <a> hyperlink.

onmousedown="function mouseDown(e){
switch (e.which) {
   case 1: alert('left'); break;
   case 2: alert('middle'); break;
   case 3: alert('right'); break; }
}"

But nothing happens If I click on a link.

Answer 1

Here's a modification of xdazz's answer that supports browsers that use e.button, normalizes the value, and stores it in e.which. The added lines are what are used in the JQuery library.

function mouseDown(e) {
  e = e || window.event;
  if ( !e.which && e.button !== undefined ) {
    e.which = ( e.button & 1 ? 1 : ( e.button & 2 ? 3 : ( e.button & 4 ? 2 : 0 ) ) );
  }
  switch (e.which) {
    case 1: alert('left'); break;
    case 2: alert('middle'); break;
    case 3: alert('right'); break; 
  }
}​

Answer 2

The html:

<a href="#" onmousedown="mouseDown(event);">aaa</a>​​​​​​​​​​​​​​​​​​​​​​​​​​​

The javascript:

function mouseDown(e) {
  e = e || window.event;
  switch (e.which) {
    case 1: alert('left'); break;
    case 2: alert('middle'); break;
    case 3: alert('right'); break; 
  }
}​

The demo.