using System.Text.RegularExpressions;
string str="aaajsbbbjsccc";
string[] sArray=Regex.Split(str,"js",RegexOptions.IgnoreCase);
foreach (string i in sArray) Response.Write(i.ToString() + "<br>");

string str="aaajbbbscccjdddseee";
string[] sArray=str.Split(new char[2]{'j','s'});
foreach(string i in sArray) Response.Write(i.ToString() + "<br>");

string str="aaajbbbjccc";
string[] sArray=str.Split('j');
foreach(string i in sArray) Response.Write(i.ToString() + "<br>");