another shader from shadertoy

hello eveyone I try to translate this very simple shadertoy to jit.gl.slab but it's not working, eveything is black.

https://www.shadertoy.com/view/4dKBDR

Can you tell me where is the problem?

this is my shader :

<jittershader name="default">
    <description> Default Slab </description>
    <param name="iChannel0" type="int" default="0" />

    <param name="iResolution" type="vec2" state="VIEWPORT" />

    <language name="glsl" version="1.2">

        <bind param="iChannel0" program="fp" />    

        <bind param="iResolution" program="vp" />

        <program name="vp" type="vertex">
<![CDATA[

varying vec2 texcoord;
uniform vec2 iResolution;

void main (void)
{
gl_Position = ftransform();
texcoord = vec2(gl_TextureMatrix[0] * gl_MultiTexCoord0);
    iResolution = vec2 (abs(gl_TextureMatrix[0][0][0]),abs(gl_TextureMatrix[0][1][1]));
}
]]>        
        </program>
        <program name="fp" type="fragment">
<![CDATA[
// FRAGMENT SHADER

varying vec2 texcoord;
uniform float iTime;

uniform sampler2DRect iChannel0;

uniform vec2 iResolution;

vec2 rand( vec2 p ) { p = vec2( dot(p,vec2(127.1,311.7)), dot(p,vec2(269.5,183.3)) ); return fract(sin(p)*43758.5453); }

void main(void)
{
vec2 uv = texcoord/iResolution.xy;

float strength = cos(iTime)*0.1;

gl_FragColor = texture2DRect( iChannel0, uv + strength*(rand(uv)-0.5));
}

]]>
        </program>
    </language>
</jittershader>