getElementById Method Internet Development Index --------------------------------------------------------------------------------Returns a reference to the first object with the specified value of the ID attribute.SyntaxoElement = document.getElementById(sIDValue)
ParameterssIDValue Required. String that specifies the value of an ID attribute. Return ValueReturns the first object with the same ID attribute as the specified value.ResIf the ID value belongs to a collection, the getElementById method returns the first object in the collection.ExampleThis example uses the getElementById method to return the first occurrence of the ID attribute value, oDiv.HideExample<SCRIPT>
function fnGetId(){
// Returns the first DIV element in the collection.
var oVDiv=document.getElementById("oDiv1");
}
</SCRIPT>
<DIV ID="oDiv1">Div #1</DIV>
<DIV ID="oDiv2">Div #2</DIV>
<DIV ID="oDiv3">Div #3</DIV>
<INPUT TYPE="button" VALUE="Get Names" onclick="fnGetId()">
Standards InformationThis method is defined in World Wide Web Consortium (W3C) Document Object Model (DOM) Level 1 . Applies To[ Object Name ]
Platform Version
Win16:
Win32:
Unix:
Mac:
Windows CE:
Version data is listed when the mouse hovers over a link, or the link has focus.
document
Move the mouse pointer over an element in the Applies To list to display availability information for the listed platforms.
ParameterssIDValue Required. String that specifies the value of an ID attribute. Return ValueReturns the first object with the same ID attribute as the specified value.ResIf the ID value belongs to a collection, the getElementById method returns the first object in the collection.ExampleThis example uses the getElementById method to return the first occurrence of the ID attribute value, oDiv.HideExample<SCRIPT>
function fnGetId(){
// Returns the first DIV element in the collection.
var oVDiv=document.getElementById("oDiv1");
}
</SCRIPT>
<DIV ID="oDiv1">Div #1</DIV>
<DIV ID="oDiv2">Div #2</DIV>
<DIV ID="oDiv3">Div #3</DIV>
<INPUT TYPE="button" VALUE="Get Names" onclick="fnGetId()">
Standards InformationThis method is defined in World Wide Web Consortium (W3C) Document Object Model (DOM) Level 1 . Applies To[ Object Name ]
Platform Version
Win16:
Win32:
Unix:
Mac:
Windows CE:
Version data is listed when the mouse hovers over a link, or the link has focus.
document
Move the mouse pointer over an element in the Applies To list to display availability information for the listed platforms.
所以改了許多javascript,
其中,Firefox最常出現的就是getElementById的問題,
在IE中,之前是習慣在驗證表單的時候直接使用form的名稱去取得下面的表單元件,
例如 : if (frm.tbxuid.value = ""){
alert("請輸入帳號");
} 但是,這樣的語法在firefox是不能跑的,
所以需要改用getElementById去取得物件,
可是,要使用getElementById的前提是表單的物件都需要有id的屬性內容,
偏偏,之前沒有加ID的習慣...
後來硬是將許多物件都加上了ID後發現...radio跟checkbox有問題...
因為radio跟checkbox的name都是一樣的,
但是id不能設定都是一樣的,(參考網址 : 細說HTML元素的ID和Name屬性的區別)
所以,radio跟checkbox要用getElementsByName來抓,
在使用getElementById時我是想說應該有ByName的但是測試了getElementByName,
發覺沒有用...後來看了上面那篇文章才發現原來是少了個s (getElementByName 應該為 getElementsByName),
後來還試了一下看看用getElementsByName抓不抓的到text或是areatext等資料,
結果發現是抓不到的,所以還是硬著頭皮將表元件一個一個檢查了...所以像上面的程式就要改成if (document.getElementById('tbxuid').value = ""){
alert("請輸入帳號");
} 要讓所有的瀏覽器都可瀏覽還真是不容易啊...除非網頁的內容很單純....
document.getElementById ("myt").style.display='none'; display是样式的一个属性，不是这个table的属性，所以需要加style。
所以你的getElementById用得没错 :)
这些东西知道去msdn查就可以了:
http://msdn.microsoft.com/library/default.asp?url=/workshop/author/dhtml/reference/methods/execcommand.asp