Use javascript parent window control to pop up only one child window_javascript skills

Recently, there are often some issues circulating on the Internet about how to control the pop-up of only one child window in the parent window. I have checked some, and most of them can only solve part of the problem or are very troublesome, and are not perfect yet. For example, someone has implemented this, using cookies. The following is an example.​
I made a pop-up window on the homepage. How can I make it pop up only once and no longer pop up when I return to the homepage?​
-------------------------------------------------- ----------------



-------------------------------------------------- ----------------

cookie
-------------------------------------------------- ----------------

This is an example randomly picked from the Internet. It seems a lot and difficult to understand. Now I will tell you a new method to ensure it looks good and is easy to use.


The MM_openBrWindow() function name is the pop-up window function name commonly used in Dreamweaver. Put this code into the page
Then you can only pop out a pop-up window. The above is the essence. The following is the complete code of a test page. Give it a try. nbsp;html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">





Untitled Document



title <script> <br>window.open("http://www.yeboss.com.cn","yeboss","width=300,height=400") <br></script><script> <br><br><!-- Begin <br>var expDays = 1; // number of days the cookie should last <br><br>var page = "only-popup-once.html"; <br>var windowprops = "width=300,height=200,location=no,toolbar=no,menubar=no,scrollbars=no,resizable=yes"; <br><br>function GetCookie (name) { <br>var arg = name + "="; <br>var alen = arg.length; <br>var clen = document.cookie.length; <br>var i = 0; <br>while (i < clen) { <br>var j = i + alen; <br>if (document.cookie.substring(i, j) == arg) <br>return getCookieVal (j); <br>i = document.cookie.indexOf(" ", i) + 1; <br>if (i == 0) break; <br>} <br>return null; <br>} <br>function SetCookie (name, value) { <br>var argv = SetCookie.arguments; <br>var argc = SetCookie.arguments.length; <br>var expires = (argc > 2) ? argv[2] : null; <br>var path = (argc > 3) ? argv[3] : null; <br>var domain = (argc > 4) ? argv[4] : null; <br>var secure = (argc > 5) ? argv[5] : false; <br>document.cookie = name + "=" + escape (value) + <br>((expires == null) ? "" : ("; expires=" + expires.toGMTString())) + <br>((path == null) ? "" : ("; path=" + path)) + <br>((domain == null) ? "" : ("; domain=" + domain)) + <br>((secure == true) ? "; secure" : ""); <br>} <br>function DeleteCookie (name) { <br>var exp = new Date(); <br>exp.setTime (exp.getTime() - 1); <br>var cval = GetCookie (name); <br>document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString(); <br>} <br>var exp = new Date(); <br>exp.setTime(exp.getTime() + (expDays*24*60*60*1000)); <br>function amt(){ <br>var count = GetCookie(&#146;count&#146;) <br>if(count == null) { <br>SetCookie(&#146;count&#146;,&#146;1&#146;) <br>return 1 <br>} <br>else { <br>var newcount = parseInt(count) + 1; <br>DeleteCookie(&#146;count&#146;) <br>SetCookie(&#146;count&#146;,newcount,exp) <br>return count <br> } <br>} <br>function getCookieVal(offset) { <br>var endstr = document.cookie.indexOf (";", offset); <br>if (endstr == -1) <br>endstr = document.cookie.length; <br>return unescape(document.cookie.substring(offset, endstr)); <br>} <br><br>function checkCount() { <br>var count = GetCookie(&#146;count&#146;); <br>if (count == null) { <br>count=1; <br>SetCookie(&#146;count&#146;, count, exp); <br><br>window.open(page, "", windowprops); <br><br>} <br>else { <br>count++; <br>SetCookie(&#146;count&#146;, count, exp); <br> } <br>} <br>// End --> <br></script> <script> <br><!-- Copyright fenggang at 2007/3/23 <br>var w=null; <br>function MM_openBrWindow(theURL,winName,features) { //v2.0 <br> if(w!=undefined&&isOpen()){ <br> w.close(); <br> } <br> w=window.open("",winName,features); <br> w.location.replace(theURL); <br>} <br>function isOpen() <br>{ <br> try <br> { <br> w.document; <br> return true; <br> } <br> catch(ex) <br> {} <br><br> return false; <br>} <br>//--> <br></script><script> <br><!-- Copyright fenggang at 2007/3/23 <br>var w=null; <br>function MM_openBrWindow(theURL,winName,features) { //v2.0 <br> if(w!=undefined&&isOpen()){ <br> w.close(); <br> } <br> w=window.open("",winName,features); <br> w.location.replace(theURL); <br>} <br>function isOpen() <br>{ <br> try <br> { <br> w.document; <br> return true; <br> } <br> catch(ex) <br> {} <br><br> return false; <br>} <br>//--> <br></script>