var initialsubj="Bekijk deze site eens"
var initialmsg="Hoi, deze site is de moeite waard om eens te bekijken: http://www.eilandvanmaurik.nl"
var good;

u = window.location;

function CheckEmailAddress(x) { var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/; if (!filter.test(x)) { return false; } return true; }

function mailThisUrl() {
  var field = document.eMailer.email;
  if (CheckEmailAddress(document.eMailer.email.value)) {
    window.location = "mailto:"+document.eMailer.email.value+"?subject="+initialsubj+"&body="+initialmsg
  }else {
    alert('Please enter a valid address.');
    field.focus();
    field.select();
  }
}