function Openwindow(new_window) {
       new_window=document.login.new_window.value;
    window.open(new_window, 0, "resizable=yes,scrollbars=yes,width=450,height=300,top=10,left=300");    
  }	
  
  function wissen(Form) {
    Form.reset();
	return false;
  } 
  
  function empty_data(message, data, name){	
  	if (data==""){
		    alert("Gelieve " + message + " in te vullen.");
		    document.forms['login'].elements[name].focus();
		    return true;
        }else {return false;}
  }


  function check_alphanum(message, data, name) {
   var j;
	 for (i=0;i<data.length;i++){
       j=data.substring(i,i+1);
       if(j!="/") { 
        if (j<"0" ||j>"9") {
          alert(message +" is niet alphanumerisch !");
          document.forms['login'].elements[name].focus();
			    return false;
        }
      }
    }
    return true;
  }

   function check_numeric(message,data, name){
	   if (isNaN(data)){   
	   	   alert(message +" is niet numeriek !");
		     document.forms['login'].elements[name].focus();
			   return false;
		 }
	   return true;    
   }
 
   function check_year(message, year, name){
     if (!isNaN(year)) {
	       if (((year >= 0 && year < 100) || (year >= 1800 && year < 2100))) { 
		          return true;
		     }
	   }
	   alert(message +" invalid year !");
	   document.forms['login'].elements[name].focus();
     return false;
   }
 
 
  function check_email(data, name){
    var place = data.indexOf("@",1);
    var point = data.indexOf(".",place+1);
    if ((place <= -1)||(data.length <=2)||(point <= 1)) {
	      alert('Gelieve een geldig e-mail adres in te geven!');
	      document.forms['login'].elements[name].focus();
	      return false;
    }	
    return true;
  }
	
  function check_date(message, data, name){	
  	var day, month, year,i,j;
	  i = data.indexOf("/",0)
	  day = data.slice(0,i);
	  j = data.indexOf("/",i+1)
	  month = data.slice(i+1,j);
	  year = data.slice(j+1,data.length)
	  if (valid_year(year)){
		   if (valid_month(month)){
			    if (valid_day(day)){
			        return true;
			    }
		   }
	   }
	   alert (message + " is geen geldige datum (dd/mm/jjjj)");
	   document.forms['login'].elements[name].focus();
	   return false;
  }
	
  function valid_year(year){
    if (!isNaN(year)) {
	      if (((year >= 0 && year < 100) || (year >= 1800 && year < 2100))) { 
		       return true;
		    }
	  }
    return false;
  }	

  function valid_month(month){
     if (!isNaN(month)) {
	       if (month >= 0 && month <= 12) { 
		         return true;
		     }
	   }
     return false;
  }
	
  function valid_day(day){
    if (!isNaN(day)) {
	      if (day >= 0 && day <= 31) { 
		        return true;
		    }
	   }
     return false;
  }

  function check_phone(message, data, name){
	  var j;
	  for (i=0;i<data.length;i++){
       j=data.substring(i,i+1);        
        if ((j<"0" || j>"9") && !( j == "/" || j == "." || j == " ")){
          alert(message  + " is geen geldig telefoonnummer !");
          document.forms['login'].elements[name].focus();
          return false;
        }
    }
	  return true;    
  }

  function valider(){
    
    var loginemail     = document.login.loginEmail.value;
    var loginwacht     = document.login.loginWacht.value;
       
    if (empty_data("E-mailadres",loginemail, 'loginEmail')) {return false;}
    else  if (!check_email(loginemail,'loginEmail')){return false;} 
   
    if (empty_data("Wachtwoord", loginwacht, 'loginWacht')){return false;}
	
    return true;
  }