Program mouse's drag and drop to a keyboard key

I'm trying to program with xbindkeys and xdotool one of my keyboard keys (key 1, the one that types 1 and !) to act like a mouse's left button, so that I can click, drag and drop, and so on. The following code did the trick:

# inside ~/.xbindkeysrc
"xdotool mousedown 1"
    1
"xdotool mouseup 1"
    1 + Release

The only problem is that, during holding the 1 key down and dragging the mouse, the release command activates even without releasing the key. So while I'm dragging something, it's dropped midway unintentionally. Is there a workaround this problem? Or is it that my keyboard key is faulty?

Edit

I was trying to suppress these false key releases by programming the 1 key to do something like this when pressed:

state = True
while state; do
    if [button released]; then
        add to counter or calculate time between last release
    if [count or time exceed limit]; then
        state = False
    fi
done

But I found a solution to my problem, with xmodmap's command:

xmodmap -e "keycode 10 = Pointer_Button1

I can click, select and drag. I am happy enough with this solution and quit on trying to implement the code above.