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_required(field,alerttxt)

{

with (field)

{

if (value==null||value=="")

  {alert(alerttxt);return false}

else {return true}

}

}

function validate_dropdown(field,alerttxt)

{

with(field)

{

if (selectedIndex==0)

{alert(alerttxt);return false}

else {return true}

}

}

function validate_form(thisform)

{

with (thisform)

{

if (validate_required(UserFirst,"First name please?")==false)

  {UserFirst.focus();return false}

if (validate_required(UserLast,"Last name please?")==false)

  {UserLast.focus();return false}

if (validate_email(UserEmail,"Please check EMAIL address.")==false)

  {UserEmail.focus();return false}

if (validate_dropdown(Topic,"Please select topic.")==false)

  {Topic.focus();return false}

if (validate_required(captcha_input,"Please complete Human field.")==false)

  {UserLast.focus();return false}



  }

  }