function ext_mnemoit() {
	var mnemoit = findSelection();
			mnemo = window.open('http://www.mnemo.org/mnemoit/index.php?mnemoit='+mnemoit, "mnemo");
  		mnemo.focus();
	}

function findSelection () {
  if (document.getSelection) {
    return document.getSelection();
  } else if (window.getSelection) {
    return window.getSelection();
  } else if (document.selection) {
    return document.selection.createRange().text;
  }
}

document.write('<input type="image" src="http://www.mnemo.org/media/images/mnemoit.002.png" onMouseDown="ext_mnemoit()" />');