--- esM.py-	2016-09-08 02:00:00.000000000 +0900
+++ esM.py	2016-09-08 02:20:00.000000000 +0900
@@ -370,10 +370,17 @@ def do_expr(expr, info):
 	if info.get('verb') >= 2:
 		print('expr={}'.format(expr))
 	(k, v) = expr[:2]
-	if k == 'kwd' and v == 'return':
-		r = do_expr( expr[2], info )
-		get_call_inf(info)['ret'] = r
-		return None
+	if k == 'kwd':
+		if v == 'return':
+			r = do_expr( expr[2], info )
+			get_call_inf(info)['ret'] = r
+			return None
+		if v == 'if':
+			if do_expr( expr[2], info ):
+				do_expr( expr[3], info )
+			elif len(expr) > 4:
+				do_expr( expr[4], info )
+			return None
 	if k == 'num':
 		return float(v)
 	if k == 'str':