function rewind(elem)
{
 window.location=elem;
 return false;
}

function getClientWidth()
{
  return document.compatMode=='CSS1Compat' && !window.opera?document.documentElement.clientWidth:document.body.clientWidth;
}

function getClientHeight()
{
  return document.compatMode=='CSS1Compat' && !window.opera?document.documentElement.clientHeight:document.body.clientHeight;
}
function isValidEmail (email)
{
 return (/^([a-z0-9_\-]+\.)*[a-z0-9_\-]+@([a-z0-9][a-z0-9\-]*[a-z0-9]\.)+[a-z]{2,4}$/i).test(email);
}


function goform(){
 var email = document.forms['feedback'].email.value;
 if(false!=isValidEmail(email)){
 document.forms['feedback'].submit();
 }
 else{alert('Вы ввели некорректный email');}
}