function show(chk) {
 this.block0=document.getElementById('m1sub');
 this.block1=document.getElementById('m2sub');
 
 switch(chk){  
 case 1:   
 if(this.block0.style.display=="none"){
 this.block0.style.display='block';
 this.block1.style.display='none'; 
 } 
 else{ 
 this.block0.style.display='none';
 this.block1.style.display='none'; 
 }
 break;  
 
 case 2:   
 if(this.block1.style.display=="none"){
 this.block0.style.display='none';
 this.block1.style.display='block';
 } 
 else{ 
 this.block0.style.display='none';
 this.block1.style.display='none'; 
 }  
 break; 
 
 case 3:   
 this.block0.style.display='none';
 this.block1.style.display='none';
 break; 
 
 case 4:   
 this.block0.style.display='none';
 this.block1.style.display='none';
 break;
 }
}

function showSub(chk) {
 this.sub0=document.getElementById('m2sub1');
 this.sub1=document.getElementById('m2sub2');
 this.sub2=document.getElementById('m2sub3');
 this.sub3=document.getElementById('m2sub4');
 
 switch(chk){  
 case 1:   
 if(this.sub0.style.display=="none"){
 this.sub0.style.display='block';
 this.sub1.style.display='none'; 
 this.sub2.style.display='none';
 this.sub3.style.display='none';  
 } 
 else{ 
 this.sub0.style.display='none';
 this.sub1.style.display='none'; 
 this.sub2.style.display='none';
 this.sub3.style.display='none';
 } 
 break;  
 
 case 2:   
 if(this.sub1.style.display=="none"){
 this.sub0.style.display='none';
 this.sub1.style.display='block'; 
 this.sub2.style.display='none';
 this.sub3.style.display='none';  
 }
 else{ 
 this.sub0.style.display='none';
 this.sub1.style.display='none'; 
 this.sub2.style.display='none';
 this.sub3.style.display='none';
 } 
 break;
 
 case 3:   
 if(this.sub2.style.display=="none"){
 this.sub0.style.display='none';
 this.sub1.style.display='none'; 
 this.sub2.style.display='block';
 this.sub3.style.display='none';  
 } 
 else{ 
 this.sub0.style.display='none';
 this.sub1.style.display='none'; 
 this.sub2.style.display='none';
 this.sub3.style.display='none';
 }
 break; 
 
 case 4:   
 if(this.sub3.style.display=="none"){
 this.sub0.style.display='none';
 this.sub1.style.display='none'; 
 this.sub2.style.display='none';
 this.sub3.style.display='block';  
 }
 else{ 
 this.sub0.style.display='none';
 this.sub1.style.display='none'; 
 this.sub2.style.display='none';
 this.sub3.style.display='none';
 }
 break;
 }
}