var top = 160;
var next = menu + 1;
var prev = menu - 1;

if (prev < 1) { 
	document.writeln("<a href='happy" + top + ".html'><img src='images/btn_prev.gif' width=61 height=12 border=0 alt='Previous'></a>    <a href='happy" + next + ".html'><img src='images/btn_next.gif' width=41 height=12 border=0 alt='Next'></a>");
} else if (next > top) { 
	document.writeln("<a href='happy" + prev + ".html'><img src='images/btn_prev.gif' width=61 height=12 border=0 alt='Previous'></a>    <a href='happy1.html'><img src='images/btn_next.gif' width=41 height=12 border=0 alt='Next'></a>");
} else {
	document.writeln("<a href='happy" + prev + ".html'><img src='images/btn_prev.gif' width=61 height=12 border=0 alt='Previous'></a>    <a href='happy" + next + ".html'><img src='images/btn_next.gif' width=41 height=12 border=0 alt='Next'></a>");
}

	
//<!-- all double quotes must be \" and no spaces -->