function validateForm() {
  var name = document.getElementById('name');
  var phone = document.getElementById('phone');
  var email = document.getElementById('email');
  var company = document.getElementById('company');
   
  phone.value = phone.value.replace(/[^0-9]/g,"");

   //cehck that data has being entered.
   if (name.value == '' || name.value == 'Name') {
     alert('Please enter a name.');
     name.focus();
     return false;
   }
    
    if (phone.value.length < 10) {
      alert ('Please enter a valid phone number.');
      phone.focus();
      return false;
    }
     
     if (email.value == '' || email.value == 'Email') {
       alert('Please enter an email address.');
       email.focus();
       return false;
     }
      
      if (company.value == '' || company.value == 'Company') {
        alert('Please enter a company name.');
        company.focus();
        return false;
      }
       
       // Check for valid phone number (just check for invliad characters)
       if (isNaN(phone.value)) {
         alert('Please enter a valid phone number.');
         phone.focus();
         return false;
       }
        
        // Check that email is valid.
        if (!isValidEmail(email.value)) {
          alert('Please enter a valid email address.');
          email.focus();
          return false;
        }
         
         // Check that a product was chosen
         if (!document.getElementById('product_SM').checked
           && !document.getElementById('product_WebSMS').checked
           && !document.getElementById('product_E2S').checked
           && !document.getElementById('product_API').checked) {
            
            alert('Please choose a product to trial.');
            document.getElementById('product_SM').focus();
            return false;
             
         }
          
          return true;
}
 
 //function to check valid email address
 function isValidEmail(strEmail){
   validRegExp = /^[^@]+@[^@]+.[a-z]{2,}$/i;
   strEmail = document.forms[0].email.value;
    
    // search email text for regular exp matches
    if (strEmail.search(validRegExp) == -1) {
      return false;
    } 
      return true; 
 }