diff --git a/pkg/bytes/buffer.cell b/pkg/bytes/buffer.cell
index ca11f6d..768353a 100644
--- a/pkg/bytes/buffer.cell
+++ b/pkg/bytes/buffer.cell
@@ -35,7 +35,7 @@ func (b *Buffer) empty() bool {
 
 func (b *Buffer) Reset() {
 	b.buf = []byte{}
-	b.off = 0
+	b.off = uint32(0)
 	b.lastRead = opInvalid
 }
 
diff --git a/pkg/math/bits/bits.cell b/pkg/math/bits/bits.cell
index 25cf052..174f5a9 100644
--- a/pkg/math/bits/bits.cell
+++ b/pkg/math/bits/bits.cell
@@ -93,7 +93,7 @@ func Len16(v uint16) int64 {
 	var n int64
 	x := v
 	if x >= uint16(1<<8) {
-		x = x >> 8
+		x = x >> uint16(8)
 		n = 8
 	}
 	return n + int64(len8tab[x])
@@ -104,11 +104,11 @@ func Len32(v uint32) int64 {
 	var n int64
 	x := v
 	if x >= uint32(1<<16) {
-		x = x >> 16
+		x = x >> uint32(16)
 		n = 16
 	}
 	if x >= uint32(1<<8) {
-		x = x >> 8
+		x = x >> uint32(8)
 		n = n + 8
 	}
 	return n + int64(len8tab[x])
@@ -167,7 +167,7 @@ func Len(x uint64) int64 {
 
 const deBruijn64 = 0x03f79d71b4ca8b09
 
-var deBruijn64tab = [64]byte{
+var deBruijn64tab = [64]uint64{
 	0, 1, 56, 2, 57, 49, 28, 3, 61, 58, 42, 50, 38, 29, 17, 4,
 	62, 47, 59, 36, 45, 43, 51, 22, 53, 39, 33, 30, 24, 18, 12, 5,
 	63, 55, 48, 27, 60, 41, 37, 16, 46, 35, 44, 21, 52, 32, 23, 11,
diff --git a/tests/examples/interface.cell b/tests/examples/interface.cell
index 037f14b..14df941 100644
--- a/tests/examples/interface.cell
+++ b/tests/examples/interface.cell
@@ -1,3 +1,4 @@
+
 import (
 	"errors"
 	"debug"
@@ -13,8 +14,8 @@ func (b *Demo) ed() uint32 {
 	return b.end
 }
 func (b *Demo) reset() {
-	b.start = 0
-	b.end = 0
+	b.start = uint32(0)
+	b.end = uint32(0)
 }
 type Range interface {
 	st() (uint32, error)
diff --git a/tests/examples/xudt.cell b/tests/examples/xudt.cell
index 20ade91..42fdab0 100644
--- a/tests/examples/xudt.cell
+++ b/tests/examples/xudt.cell
@@ -7,6 +7,8 @@ import (
 	"tx"
 	"bytes"
 	"encoding/binary"
+	"errors"
+	"blockchain"
 )
 
 const (
@@ -97,7 +99,8 @@ type XudtCell table {
 
 func Inputs() []XudtCell {
 	// todo
-	rawIns := tx.inputs()
+	raw := tx.inputs()
+
 	ins := []XudtCell{}
 	return ins
 }
@@ -132,13 +135,23 @@ func checkCellsTypeHash(cells []XudtCell, args string) bool {
 	}
 	return false
 }
-
-func loadExtensionScripts() []cell.Script {
+type CellScript table {
+	codeHash string // size == 32byte
+	hashType byte
+	args	 string
+}
+func loadExtensionScripts() []CellScript {
 	// todo
-	return []cell.Script{}
+	return []CellScript{}
+}
+
+func loadScript() CellScript {
+	raw := tx.checkedLoadScript()
+	var ret CellScript
+	return ret
 }
 func main() {
-	script := tx.checkedLoadScript()
+	script := loadScript()
 	ok := tx.scriptVerify()
 	ins := Inputs()
 	args := script.args
@@ -148,16 +161,16 @@ func main() {
 	// owner mode checking
 	var owner_mode bool
 	if owner_mode_for_input_lock && owner_mode == false {
-		owner_mode = checkInputLockHash(ins, args[0:32])
+		owner_mode = checkInputLockHash(ins, args[FLAGS_SIZE:tx.BLAKE2B_BLOCK_SIZE+FLAGS_SIZE])
 	}
 
 	if owner_mode_for_input_type && owner_mode == false {
-		owner_mode = checkCellsTypeHash(ins, args[0:32])
+		owner_mode = checkCellsTypeHash(ins, args[FLAGS_SIZE:tx.BLAKE2B_BLOCK_SIZE+FLAGS_SIZE])
 	}
 
 	outs := Outputs()
 	if owner_mode_for_output_type && owner_mode == false {
-		owner_mode = checkCellsTypeHash(outs, args[0:32])
+		owner_mode = checkCellsTypeHash(outs, args[FLAGS_SIZE:tx.BLAKE2B_BLOCK_SIZE+FLAGS_SIZE])
 	}
 
 	// parse xUDT args
@@ -208,7 +221,7 @@ func main() {
 		}
 
 		// decode ownerScript raw bytes to Script
-		var ownerScript cell.Script
+		var ownerScript CellScript
 		err := tx.executeFunc(ownerScriptHash, ownerScript.hashType, "validate", owner_mode, 0, ownerScript.args)
 		if err == SUCCESS {
 			owner_mode = true
@@ -237,7 +250,7 @@ func main() {
 	if flags == XUDTFlagsPlain {
     	return SUCCESS
   	}
-	// todo: decode extension scripts
+
 	extensionScripts := loadExtensionScripts()
 	// execute all scripts
 	for i, script := range(extensionScripts) {