function validation(form) {
      
      
if(form.first_name.value == '') {

alert('Preencher o campo Nome');
form.first_name.focus();
return false;
}
if(form.last_name.value == '') {

alert('Preencher o campo Sobrenome');
form.last_name.focus();
return false;
}
if(form.company.value == '') {

alert('Preencher o campo Empresa ');
form.company.focus();
return false;
}
if(form.email.value == '') {

alert('Preencher o campo Email');
form.email.focus();
return false;
}
if(form.phone.value == '') {

alert('Preencher o campo Telefone');
form.phone.focus();
return false;
}
if(form.city.value == '') {

alert('Preencher o campo Cidade');
form.city.focus();
return false;
}
if(form.state.value == '') {

alert('Preencher o campo Estado');
form.state.focus();
return false;
}


return true;
}