function checkfields(){
	if(document.contactform.email.value==''||document.contactform.company.value==''||document.contactform.contact.value==''){
		alert("Company Name, Contact Person and E-mail are compulsory fields!");
		return false;
	}
	else if (!isStringEmail(document.contactform.email.value)) {
		alert("Please enter a valid e-mail address.");
		return false;
		}
	else 
	return true;
}

function isStringEmail( str )
{
  if( str.length<3 ) return false;
  if( str.indexOf(" ")>0 ) return false;
  var indexOfAt  = str.indexOf("@");
  var indexOfDot = str.indexOf(".");
  return (indexOfAt>=1) && (indexOfAt==str.lastIndexOf("@")) && (indexOfAt<(str.length-3)) && (indexOfDot>=1);
}