**A child page is a parent page that pops up through window.open **To pass values to the parent page, just add window.opener before the document. Such as: 1. Parent page code:

< HTML XMLNS = “http://www.w3.org/1999/xhtml” > < Head> < Meta HTTP - equiv = “content-type” Content = “text/HTML. Charset = utf-8 ”/ > < Title> No title document title> Head> < Script language = “javascript” > The function tanchu () {       Window. The open (” Untitled - 5. HTML ”);     } Script> < Body>       < Form id=“form1” name=“form1” method=“post” action="";               < Label> < Input type=“submit” name=“button” id=“button” value=” submit”                       “Onclick =” tanchu () / >               Label> < Label> < Input type=“text” name=“textfield” id=“textfield” />               Label>       Form> < / body> < / html> 2. Subpage code:

< HTML XMLNS = “http://www.w3.org/1999/xhtml” > < Head> < Meta HTTP - equiv = “content-type” Content = “text/HTML. Charset = utf-8 ”/ > < Title> No title document title> Head> < Script language = “javascript” > The function aaa () {       Window. Opener. Document. GetElementByIdx (’ textfield). Value = ‘123123123’; } Script> < Body>       < Form id=“form1” name=“form1” method=“post” action="";               < Label> < Input type=“submit” name=“button” id=“button” value=” submit”                       “Onclick =” aaa () / >               Label>       Form> < / body> < / html> Child pages are pages in the iframe

To pass a value from a child page to the parent page, simply append parent to the document. 1. Parent page code:

< HTML XMLNS = “http://www.w3.org/1999/xhtml” > < Head> < Meta HTTP - equiv = “content-type” Content = “text/HTML. Charset = utf-8 ”/ > < Title> No title document title> Head> < Body>       < Form id=“form1” name=“form1” method=“post” action="";               < Label> < Input type=“text” name=“textfield” id=“textfield” />               Label>               < Myiframe iframe id = "" SRC =” Untitled - 3. HTML >” Iframe>       Form> < / body> < / html> 2. Subpage code

< HTML XMLNS = “http://www.w3.org/1999/xhtml” > < Head> < Meta HTTP - equiv = “content-type” Content = “text/HTML. Charset = utf-8 ”/ > < Title> No title document title> Head> < Script language = “javascript” > The function (aa) {       Var a = parent. Document. GetElementByIdx (’ textfield). The value;       Alert (a); } Script> < Body>       < Form id=“form1” name=“form1” method=“post” action="";               < Label> < Input type=“submit” name=“button” id=“button” value=” submit”                       “OnClick =” aa () / >               Label>       Form> < / body> < / html>