Calling a jquery function from code behind doesnt work

I have a jquery function called MyFunc() in a seperate .js file. I wanted to call this function in c# code behind button click event. (i.e. if data gets added successfully, call MyFunc() ). Originally this function looked like this

$(".next").click(function () {

where it will directly be called during when the asp: button is clicked.

<asp:button id="btnNext" runat="server" CssClass="next action-button" Text="Next" OnClientClick="return false"/>

So I changed the function to

function MyFunc(){}

and the button to

<asp:Button ID="btnNext" runat="server" Text="Next" CssClass="action-button" OnClick="btnNext_Click1"/>

and in code behind button click event

Page.ClientScript.RegisterClientScriptInclude(GetType(), "MyScript", "Easying.js");
Page.ClientScript.RegisterClientScriptInclude(GetType(), "MyScript", "Reg.js");
Page.ClientScript.RegisterStartupScript(GetType(), "MyScript", "MyFunc()", true);

it gives me no errors. But it doesnt work. below is the function.

var current_fs, next_fs, previous_fs; //fieldsets
var left, opacity, scale; //fieldset properties which we will animate
var animating; //flag to prevent quick multi-click glitches

$(".next").click(function() {

    if (animating) return false;
    animating = true;

    current_fs = $(this).parent();
    next_fs = $(this).parent().next();

    //activate next step on progressbar using the index of next_fs
    $("#progressbar li").eq($("fieldset").index(next_fs)).addClass("active");

    //show the next fieldset
    next_fs.show();
    //hide the current fieldset with style
    current_fs.animate({ opacity: 0 }, {
        step: function (now, mx) {
            //as the opacity of current_fs reduces to 0 - stored in "now"
            //1. scale current_fs down to 80%
            scale = 1 - (1 - now) * 0.2;
            //2. bring next_fs from the right(50%)
            left = (now * 50) + "%";
            //3. increase opacity of next_fs to 1 as it moves in
            opacity = 1 - now;
            current_fs.css({ 'transform': 'scale(' + scale + ')' });
            next_fs.css({ 'left': left, 'opacity': opacity });
        },
        duration: 800,
        complete: function () {
            current_fs.hide();
            animating = false;
        },
        //this comes from the custom easing plugin
        easing: 'easeInOutBack'
    });
});

also, as you can see, MyFunc() is used to change from one fieldset to another. my aspx page has 3 fieldsets. and a progress bar (1--2--3). The progress bar should move from one to the other. and the fieldset also shud change. the current situation is I see a the progress bar move from 1 to directly 3. and no change in the fieldset. this is where I took the code for it. As Ive mentioned above, it works perfectly when I call it directly frm the aspx page. http://codepen.io/atakan/pen/gqbIz

heres the MyFunc() !!

function MyFunc() {
var current_fs, next_fs, previous_fs; //fieldsets
var left, opacity, scale; //fieldset properties which we will animate
var animating; //flag to prevent quick multi-click glitches

if (animating) return false;
animating = true;

current_fs = $(this).parent();
next_fs = $(this).parent().next();

//activate next step on progressbar using the index of next_fs
$("#progressbar li").eq($("fieldset").index(next_fs)).addClass("active");

//show the next fieldset
next_fs.show();
//hide the current fieldset with style
current_fs.animate({ opacity: 0 }, {
    step: function (now, mx) {
        //as the opacity of current_fs reduces to 0 - stored in "now"
        //1. scale current_fs down to 80%
        scale = 1 - (1 - now) * 0.2;
        //2. bring next_fs from the right(50%)
        left = (now * 50) + "%";
        //3. increase opacity of next_fs to 1 as it moves in
        opacity = 1 - now;
        current_fs.css({ 'transform': 'scale(' + scale + ')' });
        next_fs.css({ 'left': left, 'opacity': opacity });
    },
    duration: 800,
    complete: function () {
        current_fs.hide();
        animating = false;
    },
    //this comes from the custom easing plugin
    easing: 'easeInOutBack'
});};