js只能输入数字和小数点的文本框

<input type="text" onkeydown="javascript:return isNumber(event,value);"/>

<script>
isNumber = function (e,s) {
var t = 0;
//只能输入一个小数点
if(s.indexOf(".") != -1){
t = 1;
}

if(t==1&&((event.keyCode == 190)||(event.keyCode == 110))){
return false;
}

//IE浏览器
if ($.browser.msie) {
if ( ((event.keyCode > 47) && (event.keyCode < 58)) ||  ((event.keyCode > 95) && (event.keyCode < 106)) ||
(event.keyCode == 8 || (event.keyCode == 190) || (event.keyCode == 110))) {
return true;
} else {
return false;
}
}else {
if ( ((e.which > 47) && (e.which < 58)) || ((e.which > 95) && (e.which < 106)) ||
(e.which == 8)||(e.which == 110)||(e.which == 190)) {
return true;
} else {
return false;
}
}
return true;
}
</script>