function preventSelection(element){
  var preventSelection = false;

  function addHandler(element, event, handler){
    if (element.attachEvent) 
      element.attachEvent('on' + event, handler);
    else 
      if (element.addEventListener) 
        element.addEventListener(event, handler, false);
  }
  function removeSelection(){
    if (window.getSelection) { window.getSelection().removeAllRanges(); }
    else if (document.selection && document.selection.clear)
      document.selection.clear();
  }
  function killCtrlA(event){
    var event = event || window.event;
    var sender = event.target || event.srcElement;

    if (sender.tagName.match(/INPUT|TEXTAREA/i))
      return;

    var key = event.keyCode || event.which;
    if (event.ctrlKey && key == 'A'.charCodeAt(0)) 
    {
      removeSelection();

      if (event.preventDefault) 
        event.preventDefault();
      else
        event.returnValue = false;
    }
  }
  addHandler(element, 'mousemove', function(){
    if(preventSelection)
      removeSelection();
  });
  addHandler(element, 'mousedown', function(event){
    var event = event || window.event;
    var sender = event.target || event.srcElement;
    preventSelection = !sender.tagName.match(/INPUT|TEXTAREA/i);
  });
  addHandler(element, 'mouseup', function(){
    if (preventSelection)
      removeSelection();
    preventSelection = false;
  });
  addHandler(element, 'keydown', killCtrlA);
  addHandler(element, 'keyup', killCtrlA);
}

preventSelection(document);

           
document.oncontextmenu = function(){return false;}; 


 
document.ondragstart = test;
document.onselectstart = test;
document.ontextmenu = test;
function test() {
return false
}


function ch_style(nm,chislo_poley){  
	
var nm_split = nm.split("_"); 
 group_id= new Array(chislo_poley);  
 hidden_id= new Array(chislo_poley); 
 
for (k=0;k<=chislo_poley-1;k++){
 group_id[k]='id'+k; 
 hidden_id[k]='hidden_field'+k;
}	
         
for (k=0;k<=chislo_poley-1;k++){
    if (nm_split[0]==group_id[k]){
	   this_group= k;
	   break;
	}
}
  
mas_id_for_this_gr= new Array(4);
for (i=0;i<=3;i++){
  mas_id_for_this_gr[i]='id'+this_group+'_'+i;
}
  
var decor=new Array(chislo_poley); 
  for (i=0; i<=chislo_poley-1; ++i) {
	decor[i]=new Array(4)     
  }
  
  for (i=0; i<=chislo_poley-1; i++){
 	  for (j=0; j<=3; j++){
 		 decor[i][j]=0;
      } 
  }

		if (document.getElementById(nm).className == 'not_dec'){  
	 		document.getElementById(nm).className = 'dec';  
 			for (var i = 0; i < mas_id_for_this_gr.length; i++) {
				if (mas_id_for_this_gr[i] != nm){
					document.getElementById(mas_id_for_this_gr[i]).className = 'not_dec';	
					decor[this_group][i]=0;
				}
				else{
					decor[this_group][i]=1;
					}
    		}
		}
		
 	    else {
			  document.getElementById(nm).className = 'not_dec'; 
			  for (var i = 0; i < mas_id_for_this_gr.length; i++) {
				  decor[this_group][i]=0; 
			  }
		}


this_hidden='hidden_field'+ this_group; 
var hidden_field = document.getElementById(this_hidden);  
count_notdecor=0; 
for (var i = 0; i<=3; i++) {
		if (decor[this_group][i]==1) {
		   chose_elem = i;  
		   count_notdecor=-1;   
		for_text = 'id' + this_group + '_' + i;
		var this_text =  document.getElementById(for_text).text;  
		
		   break;
		}
		else {
		count_notdecor+=1;
		}	
}

if (count_notdecor==4 || count_notdecor==0){ 
 chose_elem="empty";
}

hidden_field.value= chose_elem; 


 button='button';
 var but=document.getElementById(button); 

 count_strike_out=0;    

for (k=0;k<=chislo_poley-1;k++){
     if (document.getElementById(hidden_id[k]).value != "empty") {
         count_strike_out+=1;
     }
 }

if (count_strike_out==chislo_poley){
 but.disabled=false;

}
else {
 but.disabled=true;
}
}