You're lucky, I was just studying this earlier today.
DestroyForward() is basically used to destroy any forwards you set it to. It's found in the AMXx Core and doesn't require additional modules to run/compile.
here's an example
PHP Code:
set_task(delay,"fnDoForward")
PHP Code:
public fnDoForward()
{
new iForward = CreateMultiForward("plugin_init_delay",ET_IGNORE,FP_FLOAT),iReturn
if(iForward < 0)
return log_amx("Forward could not be created.")
if(!ExecuteForward(iForward,iReturn,delay))
return log_amx("Could not execute forward.")
return DestroyForward(iForward)
}