Code does not enter if when it should

Question

This if is correct? because if I withdraw this IF it makes the call from ajax and successfully sends the fields.

<input type="submit" class="btn btn-primary" onClick='validaFrm' value="Enviar mensagem" />
<script language="JavaScript">
function validaFrm(frm) {
    if (((frm.atividades.value !=="") && (frm.numero.value !=="") && (frm.nome.value !== "") && (frm.email.value !== "") && (frm.municipio.value !== "") && (frm.mensagem.value !== "")))
    {
         EnviaEmailInstrucao("atividades","numero","nome","email","municipio","mensagem","emailInea")
    }
    else
    {
        EnviaEmailInstrucao="Erro ao enviar";
    }
}
</script>

Answer 1

It is necessary to pass the form to the function validaFrm(), this call can be made in the onsubmit of the form. o this means that you are passing the element itself (in this case the form) to the function.

<form action="suaAction" method="post" onsubmit="validaFrm(this); return false;"