Get the position of selected text

selected text position

/*
*	Script Name:
*	Get Selected Text Position
*
*       Description:
*	Get the position of a selectedRange object.
*	
*	License:
*	MIT
*/

// Get the selected text
var range = window.getSelection().getRangeAt(0);

// Create a dummy element with the id 'pagerank' and insert this into the range
var dummy = document.createElement("span");
dummy.id = "pagemark";
range.insertNode(dummy);

// Get the dummy element
var box = document.getElementById("pagemark");
// Find it's position in the page
var y = box.offsetTop;

// Remove the dummy element
dummy.parentNode.removeChild(dummy);

return y;