The Legend of the waiting for function to end! Still no answer for that, Please Help

Hello friends!, unity is sooooo wonderful !, i love you unity! BUT i am having a problem! i have a function:

public function TestePegarLista() {

 var pathToPHP = PHP_Lista;
 var finalizou: boolean = false;
 
 var w : WWW = new WWW( pathToPHP ); //
 yield w;
 
 atualizando = "Informacoes Recebidas, Processando";    
 
 if (w.error != null)
 {
         atualizando = "Falha de Comunicacao?";
 } 
 else
 {
            
     pro_ean        = new List.<String>();
     pro_dc        = new List.<String>();
     pro_pre_ven    = new List.<String>();        

     var args : String[] =  w.text.Split(":"[0]); 
     if (args[0] != "0")            
     {
              
     registros_total = args.length;
     registros_atual = 0;

             return;

     }        

     for (var i = 1; i < args.length; i++)
     {
         var fields : String[] = args[i].Split("="[0]);  
         
         pro_ean.Add(fields[0]);
         pro_dc.Add(fields[1]);
         pro_pre_ven.Add(fields[2]);
         
         registros_atual = registros_atual + 1;
                 
     }       
     
  }           
  

}

So, I try something like

function ButtonClick() {

TestePegarLista();

if( registros_total != 0 ) { Here I can fill any var or clone buttons for example, BUT it dont wait for the LOOP FUNCTION of the other function to END !, it returns registros_total = 0!!!!! i must to double run the function to make it works, its not waiting for the TestePegarLista to end to start processing the nex step, please folks how its possible to make it works ?

Many thanks

}

}