interface_build {
    {s.random} 0
    {Generate random sites.}
    {entry sites {Output random sites list:} 0 sites}
    {entry n {Input number of sites to generate:} 0 ""}
    {entry r {Input radius of quadrats:} 0 ""}
    {checkbox -d {Use drand48() [default=rand()].} "" -d}
}