append a random number as the query string

function appendRandomQuery(){
if(!window.location.search.toString().length){
var ran = Math.round(Math.random()*10000000);
window.location.search = “?”+ran;
alert(“the random number is “+ran);
}
}

function appendRandomQueryToTop(){
if(!window.top.location.search.toString().length){
var ran = Math.round(Math.random()*10000000);
window.top.location.search = “?”+ran;
alert(“the random number is “+ran);
}
}

function appendRandomQueryPrarentWindow(){
if(!window.parent.location.search.toString().length){
var ran = Math.round(Math.random()*10000000);
window.parent.location.search = “?”+ran;
alert(“the random number is “+ran);
}
}

appendRandomQuery();

The techniques demonstrated above can be used to load an iframe twice automatically. The need for an iframe to be immediately reloaded again after loaded once is that some DOM objects are not rendered correctly the first time the page got loaded. In a google map mashup project I recently did, the first time the page gets loaded, the map was showing its top-left corner; tile images were cut-off 3/4 and the all other parts were grayed out. It seems the DOM objects were displaced to several hundreds pixels left-bottom to where they are supposed to be in the Google map. Most of the times (but not always!) reloading the page (by pressing the “Reload current page” button) will solve the issue. It happens in an iframe viewed in IE (6/7; XP sp1/2). Never happens in Firefox or Mozilla. A combination of attempts(including changing the slug in the content management system [urls for the parent window document]; getting rid of tage and using the javascript reload) seems to have fixed the bug.