function HitPointsup(){
    if (SkillPoints>0 && rebirths >=1)
        SkillPoints = SkillPoints - 1;
        HitPoints = HitPoints + 10;
        document.getElementById('SkillPoints').innerHTML = SkillPoints;
        document.getElementById("HitPoints").innerHTML = HitPoints;

Skill Tree &nbsp; &nbsp; SP:<span id="SkillPoints">0</span>
                <br />
                <br />
                <button id="HitPointsup" onclick="HitPointsup()">Hp
up</button> &nbsp; <button id="SkillPoints" onclick="Mp up()">Mp
up</button>
                <br />
                <button id="SkillPoints" onclick="Hp regen()">Hp
regen</button>
                &nbsp;