判断是否为数字(js)

function isNumber(e) {   
		    if ($.browser.msie) {   
		        if ( ((event.keyCode > 47) && (event.keyCode < 58)) ||   
		              (event.keyCode == 8) ) {   
		            return true;   
		        } else {   
		            return false;   
		        }   
		    } else {   
		        if ( ((e.which > 47) && (e.which < 58)) ||   
		              (e.which == 8) ) {   
		            return true;   
		        } else {   
		            return false;   
		        }   
		    }   
		}


onkeypress="javascript:return isNumber(event);"