function echeck(str) {
    var ALERT="Invalid e-mail address.";
    var at="@"
    var dot="."
    var lat=str.indexOf(at)
    var lstr=str.length
    var ldot=str.indexOf(dot)
    if (str.indexOf(at)==-1){
       alert(ALERT)
       return false
    }

    if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
       alert(ALERT)
       return false
    }

    if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
        alert(ALERT)
        return false
    }

     if (str.indexOf(at,(lat+1))!=-1){
        alert(ALERT)
        return false
     }

     if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
        alert(ALERT)
        return false
     }

     if (str.indexOf(dot,(lat+2))==-1){
        alert(ALERT)
        return false
     }

     if (str.indexOf(" ")!=-1){
        alert(ALERT)
        return false
     }

     return true
  }

function ValidateForm(myForm)
{
  var undefined;
  var emailID = myForm.email;
  var firstNameID = myForm.first_name;
  var lastNameID = myForm.last_name;
  var companyID = myForm.company;

  if ((firstNameID !== undefined) && (firstNameID.value == null || firstNameID.value == "")) {
    alert("Please enter your first name.");
    firstNameID.focus();
    return false;
  }
  if ((lastNameID !== undefined) && (lastNameID.value == null || lastNameID.value == "")) {
    alert("Please enter your last name.");
    lastNameID.focus();
    return false;
  }
  if ((companyID !== undefined) && (companyID.value == null || companyID.value == "")) {
    alert("Please enter your company name.");
    companyID.focus();
    return false;
  }
  if ((emailID.value == null) || (emailID.value=="")) {
    alert("Please enter your e-mail address.");
    emailID.focus();
    return false;
  }
  if (echeck(emailID.value) == false) {
    emailID.value="";
    emailID.focus();
    return false;
  }

  return true;
}