var bNames='home programs events rink newsletters volunteer contact about btncal'.split(' ');
var path='images/';
var btn=new Array();

function Button(name){
   this.on=new Image();
   this.on.src=path+name+'_h.jpg';
   this.off=new Image();
   this.off.src=path+name+'_d.jpg';
}

function rollOn(name){ 
   document[name].src=btn[name].on.src; 
}

function rollOff(name) {
   document[name].src=btn[name].off.src; 
}
for(i=0; i<bNames.length; i++) btn[bNames[i]]=new Button(bNames[i]);