vector multiply in webgl

How i can multiply two vector3 or two vector4 in webgl?
I tryed vector1 * vector2 but is don’t correct.

because i have this code for zoom on orbital camera ,but when this.m_orbitOffsetDistance become negative , i can’t zoom

zoom: function (zoom, minZoom, maxZoom) {
        if (this.m_behavior == CAMERA_BEHAVIOR_ORBIT) {
            // Moves the camera closer to or further away from the orbit
            // target. The zoom amounts are in world units.

            this.m_orbitMaxZoom = maxZoom;
            this.m_orbitMinZoom = minZoom;

            var vOffset = vec3.create();
            vec3.subtract(this.m_eye, this.m_target, vOffset);

            this.m_orbitOffsetDistance = vec3.length(vOffset);
            vec3.normalize(vOffset, vOffset);
            this.m_orbitOffsetDistance += zoom;
            //            this.m_orbitOffsetDistance = Math.min(Math.max(this.m_orbitOffsetDistance, minZoom), maxZoom);
            vec3.scale(this.m_orbitOffsetDistance, vOffset, vOffset);
            vec3.add(vOffset, this.m_target, this.m_eye);