I have one link in my webpage where user can call to other skype user.

<a href="skype:skype_username?call">Call me</a>

But when user have not skype installed in their pc one notification popup is coming.

Is there any way in any manner i can detect is skype is installed or not? so i can give custom message to install skype.

Somewhat you have to give a alternate link to download skype.Use the icon of Skype before your href and give the tool tip as click here to download skype. This is just my suggestion. I dont know how to identify whether they installed skype

According to some threads on stackoverflow, there was at some point a detection method available, but at the skype website there is no trace of it.

However, if skype is not installed, then you will get a popup that you need it.

i also found this during search, but don't know how to implement it in coding as i have no idea of action script.

<head><script type="text/javascript" src="http://download.skype.com/share/skypebuttons/js/skypeCheck.js"></script></head>
<a href="skype:skype_username?call" onclick="return skypeCheck();"> Call me on Skype </a>

page 9999999 on the howtos, no-one is ever likely to find it,
it was linked as "how to offer skype me calls from my website"
but no longer is

Yeah this works... thnx almostbob and all..