var isIE = document.all?true:false;
var isNS = document.layers?true:false;

function onlyAlpha(e) {
	var _ret = true;
	if (isIE){
	    if ((window.event.keyCode < 64 && window.event.keyCode != 32) || window.event.keyCode > 122) {
		     window.event.keyCode = 0;
		     _ret = false;
	     }
    }

    if (isNS) {
        if ((e.which < 64 && e.which !=32) || e.which > 122) {
             e.which = 0;
             _ret = false;
        }

    }   
return (_ret); 
}