if(sl<0){
Sound_Play(500, 250);
Sound_Play(1000, 250);
sl=0;

what is the 500 and 1000 stand for?
and that 250 is in period?
can someone help me to explain about this?

 

It's hard to say without more code. I have been working on something like this and use the following format:

playNote(note, timer);

Thus, it will give me the note I want, that I previously stored in an array, and then the duration for how long I wish to play it.

 

mikroC has it's own forum: http://www.mikroe.com/forum/

Here is the help for the Sound Library:
http://www.mikroe.com/esupport/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=149&nav=0,63

Help is also integrated into the mikroC application.

So it baffles me why you are asking your question here...

 

playNote(note, timer);
is it this need to declare before?
how to declare it?

 

No, you need to look up the definition in the documentation, to find out how you should use the function.

 

playNote(note, timer);
is it this need to declare before?
how to declare it?

Yes, I created a function or "driver" which will initiate whenever I put in that segment of code I showed you before. It's almost similar to a subroutine.

 

if(sl<0){
Sound_Play(500, 250);
Sound_Play(1000, 250);
sl=0;

what is the 500 and 1000 stand for?
and that 250 is in period?
can someone help me to explain about this?

If you read the help information you should find they say

Generates the square wave signal on the appropriate pin.
Parameters :

• freq_in_Hz: signal frequency in Hertz (Hz)
• duration_ms: signal duration in miliseconds (ms)

so

Sound_Play(500, 250);
Sound_Play(1000, 250);

will play a tone of 500hz for 250ms followed by a tone of 1Khz for 250ms.

You'll need to initialise the library first with Sound_Init and have an appropriate output device on the desginated pin.