function checkInput() { 
    var msg = "";
    var list = null;
    var index = null;
    var prepage = document.getElementById("prepage");

     if (document.addressform.state_name.value == "" ) {
              if (msg != "") {
              msg += "\r\n";
            }
    msg += "Please enter your State.";
     }


        
    if (document.addressform.suburb_name.value == "" &&
        document.addressform.postcode.value == "" )
         {
              if (msg != "") {
              msg += "\r\n";
            }
    msg += "Please enter either your postcode or suburb or town.";
      
    }              

 
   
     if (document.addressform.street_number.value != "") {
            if (isNaN(document.addressform.street_number.value) ||
                    document.addressform.street_number.value < 1) {
                if (msg != "") {
                    msg += "\r\n";
                }
                msg += "The street number you have entered is not a valid number.";
            }
            if (document.addressform.street_name.value == "") {
                if (msg != "") {
                    msg += "\r\n";
                }
                msg += "If you specify a street number you also need to specify a street name.";
            }
       }
      


        if (document.addressform.postcode.value != "") {
          if (! document.addressform.postcode.value.match(/^\d{4}$/) ) {
                if (msg != "") {
                    msg += "\r\n";
                }
                msg += "Postcode must have four digits.";
    }
  }
  
        if (document.addressform.street_number.value) {
            parseInt(document.addressform.street_number.value);
        }

    if (msg != "") {
        alert(msg);
        return false;
    }
    else {
        prepage.style.display = 'block'
        //alert(document.addressform.street_name.value);
        document.addressform.submit();
    }

}

var url = "imap/map.html";
var urlnojava = "nojava-map.html";

function openMap()  {
  window.open(url, "_top");
}

function noMap()  {
  window.open(urlnojava, "_top");
}

function goMap()  {
  if (navigator.javaEnabled()) 
    openMap();
  else noMap();
}