function selectanswer(id) {
   for (var i=0;i<document.getElementById('gpdcform').answer.length;i++) {
      if (document.getElementById('gpdcform').answer[i].value==id) {
         document.getElementById('gpdcform').answer[i].checked=true;
      }
   }
}

function selectletter(letter) {
   document.getElementById('gpdcform').answer.value=letter;
   document.getElementById('gpdcform').step.value=5;
   document.getElementById('gpdcform').submit();
}

function submitform(step) {
   answergiven=true;
   if (document.getElementById('gpdcform').prevstep.value=='1' || (step!=1 && document.getElementById('gpdcform').prevstep.value=='2') || (step!=1 && document.getElementById('gpdcform').prevstep.value=='3')) { 
      if (document.getElementById('gpdcform').method.value=='1') {
         answergiven=validateKeyword();
      } else {
         answergiven=validateList();
      }
   }
   if (answergiven) {
      document.getElementById('gpdcform').step.value=step;
      document.getElementById('gpdcform').submit();
   }
}

function validateKeyword() {
   //trim leading/trailing spaces
   document.getElementById('gpdcform').answer.value = document.getElementById('gpdcform').answer.value.replace(/^\s*/, '').replace(/\s*$/, ''); 

   keyword=document.getElementById('gpdcform').answer.value;
   if (keyword.length<3) {
      alert('Geef een zoekterm (min. 3 karakters) om door te kunnen.');
      return false;
   } else {
      // % " = : ; not allowed
      var re = /^[^\%\"\=\:\;\<\>]*$/i;   
      if (re.test(keyword)) {          
         return true;
      } else {
         alert('De zoekterm bevat een ongeldig karakter\n% " = : ; < > zijn niet toegestaan.');
         return false;
      }
   }
}

function validateList() {
   if (document.getElementById('gpdcform').answer.length) {
     for (var i=0;i<document.getElementById('gpdcform').answer.length;i++) {
        if (document.getElementById('gpdcform').answer[i].checked) return true;
     }
   }
   else {
      if (document.getElementById('gpdcform').answer.checked) {
        return true;
      }
   }
   
   alert('Maak een keuze om door te kunnen.');
   return false;
}

function gotoProductPage(x) {
   document.getElementById('gpdcform').productpagenr.value=x;
   submitform(5);
}