Put your function in document ready function. In the code above, maybe the function executes before txtsvalue is available so the handler is never attached. Fire up some debugger, open Console tab and see if you get object "txtsvalue" is null...
Try this:
$(document).ready (function() {
$("#<%=txtsvalue.ClientID%>").focus(function () {
alert("working well");
});
});
Or better yet:
$(document).ready (function() {
$("your-container").on("focus", "#txtsvalue", function () {
alert("working well");
});
});
in this code, "your-container" should be any parent of txtsvalue that is common to all controls you need this functionality for (may be even document) - if you need some other control added later, simply change the selector part "#txtsvalue, #txtSomeOtherControl". Classes, pseudo-classes, tags...any element creating valid jQuery selector can go there and all those elements will have the same focus function.
If this helps, please take some time to accept the solution so others may find it. Thank you.