evento botão

$(document).ready(function(){

  var combinacao;

  function montaCombinacao(){

    var selectA = $("#selectA").val();
    var selectB = $("#selectB").val();

    console.log(SelectA);
    console.log(SelectB);

    if(selectA === "Digital" && selectB === "1"){
      combinacao = "combinacao1";
    }
    else if(selectA === "Digital" && selectB === "2"){
      combinacao = "combinacao2";
    }
    else if(selectA === "Digital" && selectB === "3"){
      combinacao = "combinacao3"
    }


  }
  function montaBotao(){
    var location;

    if (combinacao === "combinacao1"){
      location = "http://google.com.br";
    }
    else if (combinacao === "combinacao2"){
      location = "http://facebook.com";
    }
    else if (combinacao === "combinacao3"){
      location = "http://youtube.com.br";
    }

    $("#download").onclick(window.location.href= location);

  }




});