js控制input控件只能输入数字

//js控制input控件只能输入数字
function OnlyinputNumber(e, obj, withFraction) {
if (!e) {
e = window.event;
}
if (e.which) {
key = e.which;
} else {
key = e.keyCode;
}
validNumber = false;
if (key == 8 //Backspace
|| key == 46 //Delete
|| key >= 35 && key <= 37 //End, Home, Left
|| key == 39 //Right
|| key == 189 //负号“-”
) {
validNumber = true;
}
if (!e.shiftKey) {
//only check shift is not pressed
if (withFraction
&& obj.value.length > 0
&& key == 190 //period
&& obj.value.indexOf(".") == -1) {
validNumber = true;
}
if (key == 48 && obj.value.length > 0) { // 0
validNumber = true;
}
if (key >= 49 && key <= 57) { // 1~9
validNumber = true;
}
}
if (!validNumber) {
if (e.preventDefault) {
e.preventDefault();
} else {
e.returnValue = false;
}
}
}