اشکال زدایی از کد

[yuttrim20]

سلام به دوستان من این کد رو دارم اما نمی دونم چرا خطا داره اگه از اساتید کسی میدونه لطفا راهنمایی کنید خیلی عجله دارم!
این کل کد:

protected void Page_Load(object sender, EventArgs e)
{
string hint = "";
Response.Expires = -1;
string [] a = new[]{
//Fill up array with names
a[1] = "Anna";
a[2] = "Brittany";
a[3] = "Cinderella";
a[4] = "Diana";
a[5] = "Eva";
a[6] = "Fiona";
a[7] = "Gunda";
a[8] = "Hege";
a[9] = "Inga";
a[10] = "Johanna";
a[11] = "Kitty";
a[12] = "Linda";
a[13] = "Nina";
a[14] = "Ophelia";
a[15] = "Petunia";
a[16] = "Amanda";
a[17] = "Raquel";
a[18] = "Cindy";
a[19] = "Doris";
a[20] = "Eve";
a[21] = "Evita";
a[22] = "Sunniva";
a[23] = "Tove";
a[24] = "Unni";
a[25] = "Violet";
a[26] = "Liza";
a[27] = "Elizabeth";
a[28] = "Ellen";
a[29] = "Wenche";
a[30] = "Vicky";
}

//get the q parameter from URL
string q = Strings.UCase(Request.QueryString["q"]);

//lookup all hints from array if length of q>0
if (Strings.Len[q] > 0) {
hint = "";
for ( int i = 1; i <= 30; i++) {
if (q == Strings.UCase(Strings.Mid(a[i], 1, Strings.Len[q]))) {
if (string.IsNullOrEmpty(hint)) {
hint = a[i];
} else {
hint = hint + " , " + a[i];
}
}
}
}

//Output "no suggestion" if no hint were found
//or output the correct values

if (string.IsNullOrEmpty(hint)) {
Response.Write("no suggestion");
} else {
Response.Write(hint);
}

}

در این قسمت زیر Strings خط قرمز داره:

string q = Strings.UCase(Request.QueryString["q"]);

//lookup all hints from array if length of q>0
if (Strings.Len[q] > 0) {
hint = "";
for ( int i = 1; i <= 30; i++) {
if (q == Strings.UCase(Strings.Mid(a[i], 1, Strings.Len[q]))) {
if (string.IsNullOrEmpty(hint)) {
hint = a[i];
} else {
hint = hint + " , " + a[i];
}
}
}
}