function validate_select(itemid,formOK,alertmsg){
  myselect = document.getElementById(itemid);
  if(myselect){
    myval = myselect[myselect.selectedIndex].value;
		if(myval == 0 && myselect.options.length>1){
      var opttext = myselect[myselect.selectedIndex].text.toLowerCase();
      if(opttext.indexOf('choose')!=-1){
  			if(formOK){
          alert(alertmsg);
  			  myselect.focus();
        }
  			formOK = false;
      }
    }
  }
  return formOK;
}

function mydebug(mytext){
  debugdiv = document.getElementById('debug');
  if(debugdiv)
    debugdiv.innerHTML += mytext + '<br />';
  else
    alert(mytext);
}

car_size_notes = new Array();
car_size_notes['petrol'] = new Array();
car_size_notes['diesel'] = new Array();
car_size_notes['petrol hybrid'] = new Array();
car_size_notes['petrol']['small'] = 'Small:  less than 1.4 litres';
car_size_notes['petrol']['medium']= 'Medium: between 1.4 and 2.0 litres';
car_size_notes['petrol']['large'] = 'Large:  greater than 2.0 litres';
car_size_notes['diesel']['small'] = 'Small:  less than 1.7 litres';
car_size_notes['diesel']['medium']= 'Medium: between 1.7 and 2.0 litres';
car_size_notes['diesel']['large'] = 'Large:  greater than 2.0 litres';
car_size_notes['petrol hybrid']['small'] = 'Small';
car_size_notes['petrol hybrid']['medium']= 'Medium: i.e. Prius';
car_size_notes['petrol hybrid']['large'] = 'Large: i.e. Honda Civic IMA';

function update_cars_values(src, dest){
  var val = src[src.selectedIndex].value;
  var rewrite_vals, cur;
  var dst = document.getElementById(dest);
  if(dst){
    rewrite_vals = car_size_notes[val];
    if(rewrite_vals){
      for(i=0;i<dst.length;i++){
        cur = dst.options[i].value;
        if(rewrite_vals[cur])
          dst.options[i].text = rewrite_vals[cur];
    	}
  	}
    //mydebug(rewrite_vals);
  }
  //mydebug(val);
}

function update_energy_fields(type){
  //mydebug(type);
  if(type=='n'){
    show_hide('quantity_main','none');
    show_hide('electricity_main','none');
  }else if(type=='y'){
    show_hide('quantity_main','block');
    show_hide('electricity_main','block');
  }
}

function show_hide(divname,display){
  myobj = document.getElementById(divname);
  if(myobj)
    myobj.style.display = display;
}

function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}