i got sound using the action. but i cannot off it.<br /><br />how to make it play once only?<br /><br />the codes is this :<br />ZERO CONDITION:<br />[code]for (int i=0; i<n; i++) {&nbsp; // Update coordinates<br />&nbsp; x[i] = xTop[i] + l*Math.sin(alpha[i]);<br />&nbsp; y[i] = yTop - l*Math.cos(alpha[i]);<br /> }<br /> <br /> // codes for calculation of zero condition based on length<br />double min = TOLERANCE;<br />for (int i=0; i<n; i++) {<br />&nbsp; for (int j=i+1; j<n; j++) {<br />&nbsp; &nbsp; double deltax = x[j]-x[i], deltay = y[j]-y[i]; <br />&nbsp; &nbsp; double allowed = 2*radius;<br />&nbsp; &nbsp; double distance = deltax*deltax+deltay*deltay-allowed*allowed;<br />&nbsp; &nbsp; if (distance<min) {<br />&nbsp; &nbsp; &nbsp; if (deltax*(omega[j]-omega[i])<0) {<br /> // take action to take if loop checks for delatx*difference of angular velocities less than zero<br />&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;ball1 = i; ball2 = j; min = distance;<br />//&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; sound = true; // testing sound on<br />&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <br />//&nbsp; &nbsp; &nbsp; }<br />//&nbsp; &nbsp; &nbsp; else { sound = false; //testing sound off<br />&nbsp; &nbsp; }<br />&nbsp; &nbsp; &nbsp; <br />&nbsp; &nbsp; &nbsp; <br />&nbsp; &nbsp; }<br />&nbsp; }<br />}<br />return min;[/code]<br /><br />and i added the acion<br />ACTION<br />[code]double aux = omega[ball1]; // assign aux to omega[ball1]<br />omega[ball1] = omega[ball2]; // assign omega[ball1] = omega[ball2], because mass same so this will work<br />omega[ball2] = aux;<br />sound = true; // sound produced added by weelk but it is non stop why?[/code]