Example code of JS delayed loading to speed up page opening

First, JS delayed Loading

The Code is as follows:
Copy codeThe Code is as follows:
<Script language = "JavaScript" src = "" id = "my"> </script>
<Script language = "JavaScript">
SetTimeout ("document. getElementById ('my'). src = 'include/... file... php';", 3000); // delay of 3 seconds
</Script>

Second, the final loading of JS

Insert the following code where Javascript is to be inserted:

<SPAN id = L4EVER> LOADING... </SPAN>

Of course, the LOADING... You can switch to your favorite small image. It looks very AJAX-effective.

Insert at the bottom of the page:
Copy codeThe Code is as follows:
<SPAN class = spanclass id = AD_L4EVER>
Your JS Code is here! </SPAN>
<Script> L4EVER. innerHTML = AD_L4EVER.innerHTML; AD_L4EVER.innerHTML = ""; </script>

Third, JS final loading

Position of the advertisement to be displayed
<Div id = "guangg1"> </div>

Ad content to be displayed
Copy codeThe Code is as follows:
<Div id = "ggad1" style = "display: none">
<Script language = "javascript" src = "/include/...... js"> </script>
</Div>

Determine whether the ad location to be displayed exists
Copy codeThe Code is as follows:
<Script language = "javascript">
Function chkdiv (divid ){
Var chkid = document. getElementById (divid );
If (chkid! = Null)
{Return true ;}
Else
{Return false ;}
} Finally, the advertisement is displayed.
If (chkdiv ('guangg1 ')){
Document. getElementById ('guangg1 '). innerHTML = document. getElementById ('ggad1'). innerHTML;
Document. getElementById ('ggad1'). innerHTML = "";
}
</Script>

SetTimeout usage

The standard syntax of setTimeout is: setTimeout (expression, time (MS.

Note the call of the first parameter as a function. Assume It is a function.

1. The function has no parameters:

Function alertV () {alert ("000 ");}

When the first parameter is not enclosed by quotation marks ("" or ''), the delay is one second:
SetTimeout (alertV, 1000 );

When the first parameter is enclosed by quotation marks, the delay is one second:
SetTimeout ("alertvs ()", 1000 );

2. function parameters:

Function alertV (event) {alert ("keyCode =" + event. keyCode );}

Set this parameter:
SetTimeout (function () {alertV (event) ;}, 1000); otherwise, the system will prompt that the parameter is not defined.