function dependantSelects(arname,sel1,sel2,newlength){
  getEl(sel1).onchange=new Function('var s2=getEl("'+sel2+'");var ar=new Array();if(!isUndefined('+arname+'[this.value]))ar='+arname+'[this.value];s2.options.length='+newlength+';for(var i=0;i<ar.length;i++)s2.options[s2.options.length]=new Option(ar[i][1],ar[i][0]);if(isFunction(s2.onchange))s2.onchange()');
}

function isUndefined(i)
{
	return typeof(i) == 'undefined';
}

function isFunction(i)
{
	return typeof(i) == 'function';
}