I have to do the cross-domain ajax,so I try the jsonp.
Then I will have to add the script element dynamiclly to the page,however I can not check its sta
For IE, think of alternate ways to check load has happened, e.g. in your script file add the line
script_myScriptUniqueName_loaded = true;
and then in the dynamic add, if script.onload is not null (before setting a callback) use window.setInterval to check for existance of script_myScriptUniqueName_loaded, with a timeout to throw error, and if exists call callback.
Remember to do window.clearInterval when you're done.