为什么我在Javascript中的功能不起作用？

Question

I am trying differents methods to implement a function, but one o them isn't working. Are this syntax correct?:

function funcao2()
        {
            alert('Tudo bem?');
        }funcao2();

I have a 'self invoking function' , an 'anonymous function' and a 'function attributed to a variable' , but the second aren't working. See the code:

<script type="text/javascript">
    //Função de auto-invocação anônima ou função recursiva anônima
    (function(){
        alert('Oi');
    })();
    //Função anônima
    document.onload = function(){
        alert('Página carregada');
    };
    //Atribuir função a uma variável e executá-la em seguida
    var funcao = function(){
        alert('Oi novamente');
    }; funcao();

Answer 1

Commented this, seems to be what the OP wanted to know, so posting it as an answer:

document.onload should be window.onload , document has the onreadystatechange event, the window loads

related:

when using the document.onreadystatechange event, check the status and readystate properties:

document.onreadystatechange = function(e)
{
    if (this.readyState === 4 && this.status === 200)
    {
        //only now, the document is loaded
        return;
    }
    //do stuff on readyState 1,2,3... <-- usefull when loading is likely to fail
}