Jquery只能输入数字与小数点示例

//只能输入数字和小数点  支持firefox 和ie
//用法   onkeydown="onlyNum(event);"
function onlyNum(event)
{
    //evt = event ? event : (window.event ? window.event : null);
    var e =  event ? event : (window.event ? window.event : null);
    var currentKey = e.charCode||e.keyCode;
    if(!((e.keyCode>=48&&e.keyCode<=57)||(e.keyCode>=96&&e.keyCode<=105)||e.keyCode == 9 || e.keyCode==8 || e.keyCode==37 || e.keyCode==38 || e.keyCode==39 || e.keyCode==40  || e.keyCode==46 || e.keyCode==110))
    {
        if (window.navigator.userAgent.indexOf("MSIE")>=1)
        {
            //如果浏览器为IE
            e.returnValue=false;    //for ie
        }else if(window.navigator.userAgent.indexOf("Firefox")>=1)
        {
            //如果浏览器为Firefox
            e.preventDefault();//for firefox
        }
    }
}