[Koha] Implementing Dropdown Menubar in OPAC Header

[SATISH]

Hi,

I have resolved my problem.

Since, I was copied down codes of the respective OPAC sections either from
blogs or examples given in websites, made it overlap.

I removed complete HTML or CSS or JS codes from
opacheader,  OpacMainUserBlock, OpacNav,  OpacNavRight.
And kept only opacheader codes. Onclick fuction, it behaved properly.
Then inspecting codes of each OPAC section one by one.
and pasting back the codes one by one and verified the header section at
each stage.
At  OpacMainUserBlock, I found,

<style type="text/css">
a:focus {
outline: none;
margin-top:20em;
}
and margin-top:2oem; was annoying.

After removing this part, whole of the OPAC Page, functions as per the
requirement.

With Thanks
Satish