try something like this
PHP Code:
stock KillEnt(ent, Float:delay)
{
decl String:addoutput[64];
Format(addoutput, sizeof(addoutput), "OnUser1 !self:kill::%f:1", delay);
SetVariantString(addoutput);
AcceptEntityInput(ent, "AddOutput");
AcceptEntityInput(ent, "FireUser1");
}
This is how you should format the output
<output name> <target name>:<input name>:<parameter>:<delay>:<max times to fire (-1 == infinite)>
this is taken from
http://developer.valvesoftware.com/wiki/AddOutput