Form中的每个对象都保留了初始值，所以可以在提交表单时，遍历Form中对象，
检查对象当前的值与初始值是否一致，就判断出了表单是否被修改了。
示例代码
1
function
IsFormChanged()
2
{
3
var isChanged = false;
4 var form = document.forms[0];
5 for (var i = 0; i < form.elements.length; i++)
6
{
7 var element = form.elements[i];
8 var type = element.type;
9 if (type == "text" || type == "hidden" || type == "textarea" || type == "button")
10 {
11 if (element.value != element.defaultValue)
12 {
13 isChanged = true;
14 break;
15
}
16 }
17 else if (type == "radio" || type == "checkbox")
18 {
19 if (element.checked != element.defaultChecked)
20 {
21 isChanged = true;
22 break;
23 }
24 }
25 else if (type == "select-one")
26 {
27 for (var j = 0; j < element.options.length; j++)
28 {
29 if (element.options[j].selected != element.options[j].defaultSelected)
30 {
31 isChanged = true;
32 break;
33 }
34 }
35 }
36 else
37 {
38 //
39 }
40 }
41
42 return isChanged;
43
}
function
IsFormChanged()2
{3
var isChanged = false;4
var form = document.forms[0];5
for (var i = 0; i < form.elements.length; i++)6
{7
var element = form.elements[i];8
var type = element.type;9
if (type == "text" || type == "hidden" || type == "textarea" || type == "button")10
{11
if (element.value != element.defaultValue)12
{13
isChanged = true;14
break;15
}16
}17
else if (type == "radio" || type == "checkbox")18
{19
if (element.checked != element.defaultChecked)20
{21
isChanged = true;22
break;23
}24
}25
else if (type == "select-one")26
{27
for (var j = 0; j < element.options.length; j++)28
{29
if (element.options[j].selected != element.options[j].defaultSelected)30
{31
isChanged = true;32
break;33
}34
}35
}36
else37
{38
//39
}40
}41
42
return isChanged;43
}
本文转自高海东博客园博客，原文链接：http://www.cnblogs.com/ghd258/archive/2007/01/12/618257.html，如需转载请自行联系原作者
