As discussed earlier, whenever the TARGET attribute is used to direct the output to a new window then the Window_name has to be specified. Whether the developer is targeting for the AREA element, BASE element or the FORM element, the window_name has to be used. A general rule with respect to the window_name says that it must begin with an alphabet. However there are some predefined special window_names which begins with an underscore sign ‘_’. Below is a list of such special window_names and their associated functions:
• _blank: When used, it directs the output to a new window. This name forces the target attribute to load the HTML document associated with the link in a separate unnamed window.
• _self: Whenever this is used the output is displayed in the same frame the user clicks in. In other words the linked document gets loaded in the same frame as the anchor. One crucial point to be noted is when the _self name is used it overrides the BASE target assigned globally.
• _parent: It can be used whenever the linked document has to be loaded into the immediate FRAMESET parent of the document. If there is no parent, then it works like the _self.
• _top: This will make the linked document to get loaded in a full browser window.
Preparing alternate document for the non-frame web browsers
In order to make the frames work properly it is essential that the web browser supports the frames. Sometimes it happens that the web client is incompatible with the frames or it has been configured not to load them. In that case an alternate document has to be prepared so that if the web browser cannot handle the frames then instead of showing an error it loads the alternate documents containing the information.
The alternate document can be prepared very easily with the help of the BODY element and the NOFRAMES tag which follows the outermost FRAMESET element. The content of the BODY element is ignored by those browsers which can read frames. Apart from this all the attributes of the NOFRAMES tag is also ignored.
Below is the HTML code which shows the usage of the NOFRAMES tag.
<HTML>
<frameset cols=”50%,50%”>
<frameset rows=”50%,50%”>
<frame src=”doc.html” >
<frame src=”doc1.html”>
</frameset>
<frameset>
<frame src=”doc2.html”>
<frame src=”doc3.html”>
<frame src=”doc4.html”>
</frameset>
</frameset>
<body>
<noframes>
This section is for those whose web browser is not compatible with frames. It will be ignored automatically if the web browser is set to read the frames. This is an excellent option to avoid any kind of errors.
</noframes>
</body>
</HTML>
As shown in the above code the NOFRAMES tag can be used at the end of the code with all the description and text which has to be displayed without the frames. Above the NOFRAMES tag, there is the normal HTML coding representing the use of nested frames and will be automatically considered when the web browser can support the frames.