[D.M]

Hello guys,
i have written a simple udf that injects particles by flow time ; the problem is when i start calculation nothing happens!!(and there is no particle injection!!) can anyone help me with this???
here is the udf:
/* the case is 2D, transient, parallel processing, the mesh is tri, in dpm method i have click on particle unsteady tracking and for injection type i choose SURFACE INJECTION and i let the velocity & totall flow rate for particles be ZERO, cause i want particles to be moved by the flow and then i hook my simple udf*/
#include "udf.h"
#include "dpm.h"
DEFINE_DPM_INJECTION_INIT(resuspention_particles, I)
{
Thread *t;
cell_t c;
Particle *p;
loop (p, I->p_init)
{
t = P_CELL_THREAD(p);
c = P_CELL(p);

if (CURRENT_TIME < 0.5)
P_POS(p)[1] = -0.11; /*before time=0.5 particles should be injected at -11
centimeter by the velocity of zero and they should be moved by the flow, it is my injection method , i specify particle's position before 0.5s*/
else
P_POS(p)[1] = -0.095; /* after 0.5s particle's should be injected at this position (9.5 centimeter)*/
}
}

/* and one other thing, i want to inject particles in a way that if i have 100 meshes on a surface so 100 particles should be injected*/