trystring test = "abcdefghijklmnopqrst";
StringBuilder sb = new StringBuilder();
for ( int i = 0; i < 20; i++)
{
sb.Append( test.Substring( i, 5 ) );
sb.Append( "-" );
i+=4;
}
StringBuilder sb = new StringBuilder();
for ( int i = 0; i < 20; i++)
{
sb.Append( test.Substring( i, 5 ) );
sb.Append( "-" );
i+=4;
}
string str1="";
for(int i=0;i<count;i=i+5)
{
str1+=str.Substring(i,5)+"-";
}
return str1.Substring(0,str1.Length-1);