回文算法(js)

function palindrome(str) {
// Good luck!
var arr=new Array();
var brr=new Array();
for (var i = 0; i <50; i++) {
str=str.replace(/[^a-zA-Z0-1]/i,"");
}
str= str.toLowerCase();
arr=str.split("");
brr=arr.reverse();
arr=str.split("");
var str1=arr.join("");
var str2=brr.join("");
/*return "str1="+str1+"    "+"str2="+str2;*/
 if(str1==str2){
return true;
}else{
    return false;
}

}

palindrome("1 eye for of 1 eye.");