javascript判断只能输入整数和小数

function clearNoNum(obj){  
        obj.value = obj.value.replace(/[^\d.]/g,""); 
        obj.value = obj.value.replace(/^\./g,"");   
        obj.value = obj.value.replace(/\.{2,}/g,".");   
        obj.value = obj.value.replace(".","$#$").replace(/\./g,"").replace("$#$","."); 
    } 
function checkKeyForFloat(value, e) { 
        var isOK = false; 
        var key = window.event ? e.keyCode : e.which; 
        if ((key > 95 && key < 106) ||                 
        (key > 47 && key < 60) ||                  
        (key == 110 && value.indexOf(".") < 0) ||  
        (key == 190 && value.indexOf(".") < 0) ||   
        key == 8 || key == 9 || key == 46 || key == 37 || key == 39 ) { 
            isOK = true; 
        } else { 
            if (window.event) //IE   
            { 
                e.returnValue = false;   //event.returnValue=false
            } 
            else //Firefox   
            { 
                e.preventDefault(); 
            } 
        } 
        return isOK; 
    } 



<input type="text" id="point_text" name="point_text" value="" onkeydown="checkKeyForFloat(this.value,event)" onkeyup="clearNoNum(this)" maxlength="10" size="10">