It looks like you are looking to have the buttons side-by-side and just spaced further apart. If that is correct, this would work.
#moveprevbtn {
position: absolute;
left: 30px;
}
#movenextbtn {
position: absolute;
right: 30px;
}
ALTERNATIVELY:
you could just add space between the two buttons like this:
#moveprevbtn {
position: relative;
margin-left: -30px;
}
#movenextbtn {
position: relative;
margin-right: -30px;
}
The first option will put your buttons 30px from the right and 30px from the left side of your view port.
The second will should simply subtract space on the opposing sides of your buttons which adds space between the two.