function distance_changeuom(e) {
	var d=document;
	var uom0 = d.getElementById('prevdisuom').value;
	var uom1 = d.getElementById('disuom').value;
	var obh   = d.getElementById('distance');
	if (uom0=='km') {
		var km = parseFloat(obh.value);
		if (uom1=='mi') {
			if (km==0.0) {
				obh.value = 0.0;
			} else {
				obh.value = Math.round(km*0.621371192);
			}
		}
	} else if (uom0=='mi') {
		var mi = parseFloat(obh.value);
		if (uom1=='km') {
			if (mi==0.0) {
				obh.value = 0.0;
			} else {
				obh.value = Math.round(mi*1.609344);
			}
		}
	}
	d.getElementById('prevdisuom').value = uom1;
}

function distance_filter(e) {
	var d=document;
	var uom = d.getElementById('disuom').value;
	var keynum=-1;
	var keychar;
	var nocheck;
	if (e.which) {
		keynum = e.which;
	} else if (window.event) {
		keynum = e.keycode;
	}
	if (keynum==-1) return true;
	if (keynum==8)  return true;
	if (keynum==32) return true;
	keychar = String.fromCharCode(keynum);
	if (keychar==".") return true;
	return /\d/.test(keychar);
}