用JS来create结点，纯JS代码生成html页面(作业练习)

<script>window.onload = function(){document.title = '表单示例';var body = document.body;// body append child beginvar center = document.createElement('center'); body.appendChild(center);var h1 = document.createElement('h1');h1.innerHTML = '增加用户';center.appendChild(h1);var hr = document.createElement('hr');center.appendChild(hr);var form = document.createElement('form');form.action = 'test.jsp';form.method = 'post';center.appendChild(form);// body append child end//form append child    beginvar input1 = document.createElement('input');input1.type = 'hidden';input1.name = 'id';input1.id = '1';form.appendChild(input1);var table = document.createElement('table');table.width = '300';form.appendChild(table);//form append child end//table append child begin// tr1 beginvar tr = document.createElement('tr');table.appendChild(tr);var td = document.createElement('td');td.innerHTML = '账号：';tr.appendChild(td);var td = document.createElement('td');var input = document.createElement('input');input.type = 'text';input.name = 'uname';td.appendChild(input);tr.appendChild(td);//tr1 end//tr2 beginvar tr = document.createElement('tr');table.appendChild(tr);var td = document.createElement('td');td.innerHTML = '密码：';tr.appendChild(td);var td = document.createElement('td');var input = document.createElement('input');input.type = 'password';input.name = 'passwd';td.appendChild(input);tr.appendChild(td);//tr2 end//tr3 beginvar tr = document.createElement('tr');table.appendChild(tr);var td = document.createElement('td');td.innerHTML = '性别：';tr.appendChild(td);var td = document.createElement('td');//radio 男 beginvar input = document.createElement('input');input.type = 'radio';input.name = 'sex';input.value = '1';input.id = 'r1';td.appendChild(input);var label = document.createElement('label');label.setAttribute('for','1');label.innerHTML = '男';td.appendChild(label);//radio 男 end//radio 女 beginvar input = document.createElement('input');input.type = 'radio';input.name = 'sex';input.value = '2';input.id = 'r2';input.checked = 'check';td.appendChild(input);var label = document.createElement('label');label.setAttribute('for','2');label.innerHTML = '女';td.appendChild(label);//radio 女 end
    tr.appendChild(td);//tr3 end//tr4 beginvar tr = document.createElement('tr');table.appendChild(tr);var td = document.createElement('td');td.innerHTML = '爱好：';tr.appendChild(td);var td = document.createElement('td');//checkbox 游戏 beginvar input = document.createElement('input');input.type = 'checkbox';input.name = 'hobby';input.value = '1';td.appendChild(input);var text = document.createTextNode('游戏');td.appendChild(text);//checkbox 游戏 end//checkbox 电影 beginvar input = document.createElement('input');input.type = 'checkbox';input.name = 'hobby';input.value = '2';input.checked = 'check';td.appendChild(input);var text = document.createTextNode('电影');td.appendChild(text);//checkbox 电影 end//checkbox 音乐 beignvar input = document.createElement('input');input.type = 'checkbox';input.name = 'hobby';input.value = '3';input.checked = 'check';td.appendChild(input);var text = document.createTextNode('音乐');td.appendChild(text);//checkbox 音乐 end//checkbox 运动 beginvar input = document.createElement('input');input.type = 'checkbox';input.name = 'hobby';input.value = '4';td.appendChild(input);var text = document.createTextNode('运动');td.appendChild(text);//checkbox 电影 end
    tr.appendChild(td);//tr4 end//tr5 beginvar tr = document.createElement('tr');table.appendChild(tr);var td = document.createElement('td');td.innerHTML = '年级：';tr.appendChild(td);var td = document.createElement('td');var sel = document.createElement('select');sel.name = 'grade';td.appendChild(sel);var opt1 = new Option('一年级',1);var opt2 = new Option('二年级',2);var opt3 = new Option('三年级',3);opt3.setAttribute('selected',true);var opt4 = new Option('四年级',4);sel.appendChild(opt1);sel.appendChild(opt2);sel.appendChild(opt3);sel.appendChild(opt4);tr.appendChild(td);//tr5 end//tr6 beginvar tr = document.createElement('tr');table.appendChild(tr);var td = document.createElement('td');td.innerHTML = '相片：';tr.appendChild(td);var td = document.createElement('td');var input = document.createElement('input');input.type = 'file';input.name = 'picture';td.appendChild(input);tr.appendChild(td);//tr6 end//tr7 beginvar tr = document.createElement('tr');table.appendChild(tr);var td = document.createElement('td');td.innerHTML = '备注：';tr.appendChild(td);var td = document.createElement('td');var textarea = document.createElement('textarea');textarea.name = 'note';textarea.cols = 30;textarea.rows = 5;textarea.innerHTML = '中国';td.appendChild(textarea);tr.appendChild(td);//tr7 end//tr8 beginvar tr = document.createElement('tr');tr.align = 'center';table.appendChild(tr);var td = document.createElement('td');td.setAttribute('colspan','2');var input = document.createElement('input');input.type = 'submit';input.value = '提交';td.appendChild(input);var input = document.createElement('input');input.type = 'reset';input.value = '重置';td.appendChild(input);var input = document.createElement('input');input.type = 'button';input.value = '按钮';input.onclick = 'alert(1)';td.appendChild(input);var button = document.createElement('button');button.innerHTML = '增加';var img = document.createElement('img');img.src = 'open.png';button.appendChild(img);td.appendChild(button);tr.appendChild(td);//tr8 end//table append child end
}
</script>