JavaScript如何判断从表单中获取的信息判断是否是正整数

function jumpPage(p){
document.forms[0].action = "<%=request.getContextPath()%>/forms/tOtherSPURL.do?page="+p;
document.getElementById("actionID").value = 0;

document.forms[0].submit();
}

function go(){
var jump1 = document.all.jump.value;
if( !isInteger(jump1) || jump1<1)
{
jump1 = 1;
}
jumpPage(jump1);
}

function isInteger(inputStr) {
var reg = new RegExp("^[0-9]*$");
return reg.test(inputStr);
}