diff --git a/impl_darwin.go b/impl_darwin.go
index 9fcf941..dfe4c7c 100644
--- a/impl_darwin.go
+++ b/impl_darwin.go
@@ -14,7 +14,7 @@ import (
 )
 
 func setAgentInfo() {
-	// get UID
+	// get UID of current user
 	usr, err := user.Current()
 	if err != nil {
 		fmt.Printf("Error: cannot get user ID: %s\n", err)
@@ -23,6 +23,7 @@ func setAgentInfo() {
 	uid := usr.Uid
 
 	// get GPG Agent PID
+	// look for gpg-agent running as the current user:
 	output, err := exec.Command("pgrep", "-U", uid, "gpg-agent").Output()
 	if err != nil {
 		fmt.Printf("Error: %s\n", err)
@@ -30,6 +31,7 @@ func setAgentInfo() {
 	} else {
 		fmt.Printf("gpg-agent process number is %s\n", output)
 	}
+	// trim trailing /n and convert to int
 	pid, err := strconv.Atoi(string(output[:len(output)-1]))
 	if err != nil {
 		fmt.Printf("Integer conversion failed: %s\n", err)
@@ -37,6 +39,7 @@ func setAgentInfo() {
 	}
 
 	// find agent socket file
+	// find unix domain sockets opened by the current user's gpg-agent
 	cmd := exec.Command("lsof", "-w", "-Fn", "-u", uid, "-baUcgpg-agent")
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {
@@ -49,6 +52,7 @@ func setAgentInfo() {
 		fmt.Printf("Error: cannot run lsof: %s\n", err)
 	}
 
+	// look for a socket named "S.gpg-agent"
 	filename := ""
 	for scanner.Scan() {
 		x := scanner.Text()
@@ -70,6 +74,8 @@ func setAgentInfo() {
 	s := fmt.Sprintf("%s:%d:1", filename, pid)
 	fmt.Printf("GPG_AGENT_INFO = %s\n", s)
 	os.Setenv("GPG_AGENT_INFO",s)
+
+	// gpg-agent is running, so use GPGPrompt as password prompt
 	ask = GPGPrompt
 }
 
diff --git a/main.go b/main.go
index 841baa9..7643750 100644
--- a/main.go
+++ b/main.go
@@ -176,7 +176,7 @@ func GPGPrompt(keys []openpgp.Key, symmetric bool) ([]byte, error) {
 }
 
 func (s *Store) Decrypt(name string, prompts ...func() []byte) (string,error) {
-	if len(prompts) > 0 {
+	if ask == nil {
 		ask = AskPass(prompts...)
 	}
 	file := path.Join(s.Dir, strings.Join([]string{name,".gpg"},""))