How to remove a border on an input element? Think it's easy, well please enlighten my day people! Thanks

Ok, so http://www.balanceosteopathy.co.uk/hidden/about.php is the site, half way down you will see h1 "What do Osteopathy treat" next to this is an arrow, WITH A BORDER around the image. Anyone who can remove this border can be owed a favor for repayment and a big electronic hug :)

<h1 class="random">What do Osteopaths treat?</h1>
<input type=image name=type id='bt1' value='Show Layer' onclick="setVisibility('sub3');";>
<p class="random">   Learn More</p>

The css is just changing the image when hovering over the input type=image element.

input[type=image] {
    background-image: url(http://platesrecords.co.uk/image/arrow-right.gif);
    background-repeat: no-repeat;
    background-position: 50% 50%;
    width: 40px;
    height: 40px;
}
input[type=image]:hover,
input[type=image]:active,
input[type=image]:focus {
    background-image: url(http://platesrecords.co.uk/image/arrow-down.gif);
}

JS if helps, think its a html css issue but hey just in-case it is not. The js is basically hiding a div for me when the arrow is clicked.

function setVisibility(id) {
if(document.getElementById('bt1').value=='Hide Layer'){
document.getElementById('bt1').value = 'Show Layer';
document.getElementById(id).style.display = 'inline';
}else{
document.getElementById('bt1').value = 'Hide Layer';
document.getElementById(id).style.display = 'none';
}
}

O yea there is more, if you would like to receive the hug promised above you need to also solve this issue :)

Currently the image slideshow on http://www.balanceosteopathy.co.uk/hidden/index.php with all the lovely people and babies on it is also meant to be controlled by the box with arrows, which currently does nothing. Can anyone help with turning the box with arrows into something that actually works, like when you click an arrow the image moves left or right. This would be great, every approach I have made failed. 'This is not what I signed up for' your thinking and your right but your'e a good person and you do want to help me who is also a good but very tired person.

Many thanks for even just reading this.

May peace be with you.