<p id="scope2" style="color:red"></p>

function echo(p, html) {
            p.innerHTML += html + '<br/>';
        }
　　　　 var pscope2 = document.getElementById('scope2');
        echo(pscope2, typeof param); //结果:undefined
        var param = 'defined';
        echo(pscope2, typeof param); //结果:string

echo(pscope2, typeof scope2); //结果:function
        echo(pscope2, typeof func); //结果:undefined
        function scope2() { //函数定义式
        };
        var func = function() { //函数表达式
        };
        echo(pscope2, typeof func); //结果:function

<script type="text/javascript">
　　　　echo(pscope2, typeof scope_next2);//结果:undefined
</script>
<script type="text/javascript">
        function scope_next2() {
        };
</script>

<script type="text/javascript">
　　　　function scope_next2() {//以段为处理单元
            pscope2.innerHTML += 'in first scope_next2<br/>';
        };
        //echo(pscope2, typeof scope_next2);//结果:undefined
        scope_next2();
</script>
<script type="text/javascript">
　　　　 var pscope2 = document.getElementById('scope2');
        function scope_next2() {
            pscope2.innerHTML += 'in second scope_next2<br/>';
        }
        scope_next2();
</script>