function validate_required(field,alerttxt)
{
with (field)
  {
  if (value==null||value=="")
    {
    alert(alerttxt);return false;
    }
  else
    {
    return true;
    }
  }
}

function validate_email(field,alerttxt)
{
with (field)
  {
  apos=value.indexOf("@");
  dotpos=value.lastIndexOf(".");
  if (apos<1||dotpos-apos<2)
    {alert(alerttxt);return false;}
  else {return true;}
  }
}

function validate_form(thisform)
{
with (thisform)
  {
  if (validate_required(location,"Location field can not be empty.")==false)
  {location.focus();return false;}
  if (validate_required(patient_first_name,"Fist Name field can not be empty.")==false)
  {patient_first_name.focus();return false;}
  if (validate_required(patient_last_name,"Last Name field can not be empty.")==false)
  {patient_last_name.focus();return false;}
  if (validate_required(d_o_b,"Please, enter your date of birth.")==false)
  {d_o_b.focus();return false;}
  if (validate_required(street_name,"Street Name field can not be empty.")==false)
  {street_name.focus();return false;}
  if (validate_required(city,"Please, enter a city name.")==false)
  {city.focus();return false;}
  if (validate_required(state,"Please, enter a state name.")==false)
  {state.focus();return false;}
  if (validate_required(zip_code,"Please, enter a zip code.")==false)
  {zip_code.focus();return false;}
  if (validate_required(home_phone,"Please, enter a home phone. ")==false && validate_required(cell_phone,"Please, enter a sell phone.")==false)
  {home_phone.focus();return false;}
  if (validate_required(email,"Please, enter an email.")==false)
  {email.focus();return false;}
  if (validate_email(email,"Not a valid e-mail address!")==false)
  {email.focus();return false;}
  }
}