Javascript generates infinite drop-down list implementation code_javascript skills

//Company two-dimensional array data source
Office = [
["Dept", "ParentDept"],
["Business Department", "0"],
["Technology Department", "0"],
["Marketing Department ", "0"],
["www.yongfa365.com", "Business Department"],
["Business Department Xiao Yang", "Business Department"],
["Business Department Xiaocai" ", "Business Department"],
["Technology Department Lao Liu", "Technology Department"],
["Technology Department Lao Yang", "Technology Department"],
["Technology Department Lao Yang" dish", "Technical Department"],
["Mr. Liu of Marketing Department", "Marketing Department"],
["Mr. Yang of Marketing Department", "Marketing Department"],
["Marketing Department" "Rookie", "Marketing Department"]
]

//Province and city three-dimensional array data source
City3 = [
["Dept", "ParentId", "Id"],
["Beijing", "0", "010"],
["Shanxi", "0", "0359"],
["Chaoyang District", "010", "001"] ,
["Haidian District", "010", "002"],
["Dugezhuang", "001", "101"],
["Shilibao", "001" , "102"],
["Zhongguancun", "002", "201"],
["Shangdi", "002", "202"],
["Yuncheng area", "0359", "301"],
["Taiyuan City", "0359", "302"],
["Yongji City", "301", "311"],
[ "Community", "302", "312"]
];

//FillSelectTree("nowhaha", City3, "0", "311", -1)
//Select Control ID, data source, parent value, selected value, level (used to generate separators)
function FillSelectTree(SelectId, ArrObj, ParentValue, SelectedValue, NowI) {
StrObj = eval(document.getElementById (SelectId));

NowI ;

//Determine whether it is a secondary data source or a third-level data source
if (ArrObj[0].length == 2)
{ ArrNum = 0; }
else
{ ArrNum = 2; }

//Generate all Option
for (var i = 0; i < ArrObj.length; i ) {
if (ArrObj[i][1] == ParentValue) {
StrObj.options[StrObj.length] = new Option(String("　", NowI) ArrObj[i][0], ArrObj[i ][ArrNum]);

//Select the default value
if (ArrObj[i][ArrNum] == SelectedValue) {
StrObj.options[StrObj.length - 1].selected = true;
}

//Traverse
FillSelectTree(SelectId, ArrObj, ArrObj[i][ArrNum], SelectedValue, NowI);
}
}
}


//How many times to copy the string
function String(str, nowi) {
strtemp = "";
for (var i = 0; i < nowi; i ) {
strtemp = str;
}
return strtemp;
}