diff --git a/24_day/bootpack.c b/24_day/bootpack.c
index 15044bc..541aa30 100644
--- a/24_day/bootpack.c
+++ b/24_day/bootpack.c
@@ -42,8 +42,8 @@ void HariMain(void)
 	};
 	int key_to = 0, key_shift = 0, key_leds = (binfo->leds >> 4) & 7, keycmd_wait = -1;
 	struct CONSOLE *cons;
-	int j, x, y;
-	struct SHEET *sht;
+	int j, x, y, mmx = -1, mmy = -1;
+	struct SHEET *sht = 0;
 
 	init_gdtidt();
 	init_pic();
@@ -267,21 +267,39 @@ void HariMain(void)
 					if (my > binfo->scrny - 1) {
 						my = binfo->scrny - 1;
 					}
-					
+
 					sheet_slide(sht_mouse, mx, my);/* 包含sheet_refresh含sheet_refresh */
 
-					if ((mdec.btn & 0x01) != 0) { /* 按下左键、移动sht_win */
-						for (j = shtctl->top - 1; j > 0; j--) {
-							sht = shtctl->sheets[j];
-							x = mx - sht->vx0;
-							y = my - sht->vy0;
-							if (0 <= x && x < sht->bxsize && 0 <= y && y < sht->bysize) {
-								if (sht->buf[y * sht->bxsize + x] != sht->col_inv) {
-									sheet_updown(sht, shtctl->top - 1);
-									break;
+					if ((mdec.btn & 0x01) != 0) { /* 按下左键 */
+						if (mmx < 0) {
+							/*如果处于通常模式*/
+							/*按照从上到下的顺序寻找鼠标所指向的图层*/
+							for (j = shtctl->top - 1; j > 0; j--) {
+								sht = shtctl->sheets[j];
+								x = mx - sht->vx0;
+								y = my - sht->vy0;
+								if (0 <= x && x < sht->bxsize && 0 <= y && y < sht->bysize) {
+									if (sht->buf[y * sht->bxsize + x] != sht->col_inv) {
+										sheet_updown(sht, shtctl->top - 1);
+										if (3 <= x && x < sht->bxsize - 3 && 3 <= y && y < 21) {
+											mmx = mx; /*进入窗口移动模式*/
+											mmy = my;
+										}
+										break;
+									}
 								}
 							}
+						} else {
+							/*如果处于窗口移动模式*/
+							x = mx - mmx; /*计算鼠标的移动距离*/
+							y = my - mmy;
+							sheet_slide(sht, sht->vx0 + x, sht->vy0 + y);
+							mmx = mx; /*更新为移动后的坐标*/
+							mmy = my;
 						}
+					} else {
+						/*没有按下左键*/
+						mmx = -1; /*返回通常模式*/
 					}
 
 				}