onclick w3schools san code example
Example 1: javascript onclick
var myElem = document.getElementByID('ElemID');
myElem.onclick = function() {
//do stuff
}
Example 2: javascript onclick
// The element id (TheElementID) and var name (myElement) can be named anything.
var myElement = document.getElementByID('TheElementID');
myElement.onclick = function() {
// Carry out a function here...
}