Fake "click" to activate an onclick method

Once you have selected an element you can call click()

document.getElementById('link').click();

see: https://developer.mozilla.org/En/DOM/Element.click

I don't remember if this works on IE, but it should. I don't have a windows machine nearby.

If you're using JQuery you can do:

$('#elementid').click();

I could be misinterpreting your question, but, yes, this is possible. The way that I would go about doing it is this:

var oElement = document.getElementById('elementId');   // get a reference to your element
oElement.onclick = clickHandler; // assign its click function a function reference

function clickHandler() {
    // this function will be called whenever the element is clicked
    // and can also be called from the context of other functions
}

Now, whenever this element is clicked, the code in clickHandler will execute. Similarly, you can execute the same code by calling the function from within the context of other functions (or even assign clickHandler to handle events triggered by other elements)>

var clickEvent = new MouseEvent('click', {
  view: window,
  bubbles: true,
  cancelable: true
});
var element = document.getElementById('element-id'); 
var cancelled = !element.dispatchEvent(clickEvent);
if (cancelled) {
  // A handler called preventDefault.
  alert("cancelled");
} else {
  // None of the handlers called preventDefault.
  alert("not cancelled");
}

element.dispatchEvent is supported in all major browsers. The example above is based on an sample simulateClick() function on MDN.

Using javascript you can trigger click() and focus() like below example

document.addEventListener("click", function(e) {
  console.log("Clicked On : ",e.toElement);
},true);
document.addEventListener('focus',function(e){
  console.log("Focused On : ",e.srcElement);
},true);

document.querySelector("#button_1").click();
document.querySelector("#input_1").focus();

<input type="button" value="test-button" id="button_1">
<input type="text" value="value 1" id="input_1">
<input type="text" value="value 2" id="input_2">

This is a perfect example of where you should use a javascript library like Prototype or JQuery to abstract away the cross-browser differences.

just call "onclick"!

here's an example html:

<div id="c" onclick="alert('hello')">Click me!</div>
<div onclick="document.getElementById('c').onclick()">Fake click the previous link!</div>

For IE there is fireEvent() method. Don't know if that works for other browsers.

I haven't used jQuery, but IIRC, the first method mentioned doesn't trigger the onclick handler.

I'd call the associated onclick method directly, if you're not using the event details.