function checkform ( form )
{
  if (form.required_email.value == "") {
    alert( "Please enter your email address." );
    form.required_email.focus();
    return false ;
  }
  return true ;
}

function SwapImage(image,text,btn) {
  image.src="button.php?text=" + text + "&btn=" + btn
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}