nothing wrong with :
				if (stat == "heal")
				{
					ISkillHandler handler = SkillHandler.getInstance().getSkillHandler(SkillType.HEAL);
					if (handler == null)
					{
						_log.severe("Couldn't find skill handler for HEAL.");
						continue;
					}
					L2Object tgts[] = new L2Object[]{target};
					try {
						handler.useSkill(caster, this, tgts);
					} catch (IOException e) {
						_log.log(Level.WARNING, "", e);
					}



?


skill :

<skill id="1020" levels="27" name="Vitalize">
  <table name="#mpConsume">
     87  89  92  97  97 99 104 107 109 112 
    114 117 118 118 120 123 124 127 129 132 
    133 135 137 139 140 142 144
  </table>
  <table name="#power">
    440.0 454.0 467.0 494.0 508.0 521.0 548.0 562.0 575.0 588.0
    602.0 615.0 627.0 640.0 653.0 665.0 677.0 689.0 700.0 711.0
    722.0 733.0 743.0 753.0 763.0 772.0 780.0
  </table>
  <table name="#negatePower">
    3.0 3.0 3.0 3.0 3.0 7.0 7.0 7.0 7.0 7.0
    7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 9.0 9.0
    9.0 9.0 9.0 9.0 9.0 9.0 9.0
  </table>
  <set name="mpConsume" val="#mpConsume"/>
  <set name="power" val="#power"/>
  <set name="target" val="TARGET_ONE"/>
  <set name="hitTime" val="5000"/>
  <set name="reuseDelay" val="10000"/>
  <set name="skillTime" val="5000"/>
  <set name="skillType" val="NEGATE"/>
  <set name="isMagic" val="true"/>
  <set name="operateType" val="OP_ACTIVE"/>
  <set name="castRange" val="600"/>
  <set name="negateStats" val="HEAL POISON BLEED"/>
  <set name="negatePower" val="#negatePower"/>
  <for>
  </for>
</skill>