Máscaras Brasileiras JS

/* Máscaras ER */
function mascara(o,f){
    v_obj=o
    v_fun=f
    setTimeout("execmascara()",1)
}
function execmascara(){
    v_obj.value=v_fun(v_obj.value)
}
function mtel(v){
    v=v.replace(/\D/g,"");             //Remove tudo o que não é dígito
    v=v.replace(/^(\d{2})(\d)/g,"($1) $2"); //Coloca parênteses em volta dos dois primeiros dígitos
    v=v.replace(/(\d)(\d{4})$/,"$1-$2");    //Coloca hífen entre o quarto e o quinto dígitos
    return v;
}
function mCNPJ(v){
	v=v.replace(/\D/g,"");
	v=v.replace(/^(\d{2})(\d)/,"$1.$2");
	v=v.replace(/^(\d{2})\.(\d{3})(\d)/,"$1.$2.$3");
	v=v.replace(/\.(\d{3})(\d)/,".$1/$2");
	v=v.replace(/(\d{4})(\d)/,"$1-$2");
	return v;
}
function mcpf(v) {
  v=v.replace(/\D/g,"");
	v=v.replace(/(\d{3})(\d)/,"$1.$2");
	v=v.replace(/(\d{3})(\d)/,"$1.$2");
	v=v.replace(/(\d{3})(\d{1,2})$/,"$1-$2");
	return v;
}
function mCEP(v){
	v=v.replace(/\D/g,"");
	v=v.replace(/^(\d{2})(\d)/,"$1.$2");
	v=v.replace(/\.(\d{3})(\d)/,".$1-$2");
	return v;
}
function mNum(v){
	v=v.replace(/\D/g,"");
	return v;
}
function id( el ){
    return document.getElementById( el );
}
window.onload = function(){
    if (id('acf-field_59dd151f7f5c3')) {
      id('acf-field_59dd151f7f5c3').onkeypress = function(){
          mascara( this, mtel );
      }
    }

    if (id('acf-field_59dd15337f5c4')) {
      id('acf-field_59dd15337f5c4').onkeypress = function(){
        mascara( this, mtel );
      }
    }

    if (id('telefone')) {
      id('telefone').onkeypress = function(){
          mascara( this, mtel );
      }
    }

    if (id('celular')) {
      id('celular').onkeypress = function(){
        mascara( this, mtel );
      }
    }
    if (id('cpf')) {
      id('cpf').onkeypress = function(){
        mascara( this, mcpf );
      }
    }
    if (id('cep')) {
      id('cep').onkeypress = function(){
        mascara( this, mcep );
      }
    }
    if (id('cnpj')) {
      id('cnpj').onkeypress = function(){
        mascara( this, mcnpj );
      }
    }
}