private void setElementField(String str1, String str2, float x) {
		int lb = str1.indexOf("[");
		int rb = str1.indexOf("]");
		double z = parseMathExpression(str1.substring(lb + 1, rb));
		if (Double.isNaN(z))
			return;
		int i = (int) Math.round(z);
		if (i < 110 || i >= 113) {
			out(ScriptEvent.FAILED, "Element " + i + " isn't generic particle.");
			return;
		}
		String symbol = null;
		switch (i) {
		case 110:
			symbol = "X1";
			break;
		case 111:
			symbol = "X2";
			break;
		case 112:
			symbol = "X3";
			break;
		case 113:
			symbol = "X4";
			break;
		}
		String s = str2.toLowerCase().intern();
		boolean b = true;
		if (s == "mass") {
			model.setElementMass(symbol, x);
			for (i = 0; i < model.getAtomCount(); i++)
				model.atom[i].mass = x;
		}
		else if (s == "sigma") {
			model.setElementSigma(symbol, x);
			for (i = 0; i < model.getAtomCount(); i++) {
				model.atom[i].sigma = x;
				view.getViewer().setAtomSize(i, x * 1000);
			}
		}
		else if (s == "epsilon") {
			model.setElementEpsilon(symbol, x);
			for (i = 0; i < model.getAtomCount(); i++)
				model.atom[i].epsilon = x;
		}
		else {
			out(ScriptEvent.FAILED, "Cannot set property: " + str2);
			b = false;
		}
		if (b) {
			view.repaint();
			model.notifyChange();
		}
	}