function emailcheck(str) {
var at="@"
var dot="."
var lat=str.indexOf(at)
var lstr=str.length
var ldot=str.indexOf(dot)
if (str.indexOf(at)==-1){
alert("The eMail address '@' convention appears to be invalid.")
return false
}
if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
alert("The eMail address '@' convention appears to be invalid.")
return false
}
if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
alert("The eMail address 'dot' convention appears to be invalid.")
return false
}
if (str.indexOf(at,(lat+1))!=-1){
alert("The eMail address '@' convention appears to be invalid.")
return false
}
if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
alert("The eMail address 'dot' convention appears to be invalid.")
return false
}
if (str.indexOf(dot,(lat+2))==-1){
alert("The eMail address 'dot' convention appears to be invalid.")
return false
}
if (str.indexOf(" ")!=-1){
alert("The eMail address spacing convention appears to be invalid.")
return false
}
return true 
  }
  function ValidateForm()
  {
  var textfield4=document.form1.textfield4

  if ((textfield4.value==null)||(textfield4.value==""))
  {
  alert("Please Enter your Email Address")
  textfield4.focus()
  return false
  }
  if (emailcheck(textfield4.value)==false)
  {
  textfield4.value=""
  textfield4.focus()
  return false
  }
  return true
  }