A bit of technology

Today I was fighting with IE8 for a few hours because this stupid browser enjoys torturing web-developers. There is a method in JavaScript in IE called window.showModalDialog which opens modal popup. This method returns value which was set by page opened in such popup. This is done by setting window.returnValue inside popup, but guess what? It does not work! There are a lot of reasons for this feature not to work and a lot of local workarounds, but that all suck, so I killed a lot of time to find An Ultimate Solution to situations when returnValue is undefined. And it is quite simple (: As always!

On caller page create a callback function which will be called from popup to update data:

function modalCallback(newData) {
    globalVar = newData;
    // globalVar is some external variable you would like to update.
    // Actually you may place any code here!
}

Then prepare dialogArguments on a caller page and execute showModalDialog:

var args = {'callback': modalCallback};
window.showModalDialog('popup.html', args);
// Put the code to process recieved data here!

And now for a modal popup. When you ready to send data back to parent window just call your callback function!

window.dialogArguments.callback(dataFromPopup);

That's it!

P.S. I hope people using this tip do know JavaScript and programming in general.