/*
      (c) Poort80 B.V. 2007
      P.M. Boudewijn
      
   */
   
   function initform( formId )
   {
      var form = document.getElementById( formId );  
      if ( form )
      {
         for ( var x=0; x < form.elements.length; x++ )
         {
            if ( form.elements[x].type == 'text' || form.elements[x].type == 'submit' || form.elements[x].type == 'radio'  || form.elements[x].type == 'checkbox' )
            {
               form.elements[x].onkeyup = formfield_keypress;
            }
         }  
      }
   }
   
   function formfield_keypress( event )
   {
      var evt = event || window.event;     
      var form = document.getElementById( "formKoopDiePas" );      
      var key = event ? event.keyCode : ( evt ? evt.keyCode : '' ); // 38 = arrow up, 40 = arrow down
      var el = evt.srcElement || evt.target;
      var newElm = null;
        
      if ( el && ( key == 38 || key == 40 ) && form && el )
      {
         var elmIdx = -1;
         // find form field
         for ( var x=0; x < form.elements.length; x++ )
         {
            if ( form.elements[x].name == el.name )
            {               
               if ( key == 38 )
               {
                  if ( x > 0 )
                  {
                     newElm = form.elements[ x - 1 ];
                  }
                  else
                  {
                     // no field above
                  }
               }
               else if ( key == 40 )
               {
                  if ( x < form.elements.length - 1 )
                  {
                     newElm = form.elements[ x + 1 ];
                  }
                  else
                  {
                     // no field above
                  }
               }
            }
         }
      
         // focus
         if ( newElm && ( newElm.type == 'text' || newElm.type == 'submit' || newElm.type == 'radio'  || newElm.type == 'checkbox' ) )
         {
            try
            {
               newElm.focus();
            }
            catch ( e )
            {
               //
            }
         }
      }
   }