//获取td的x坐标，ObjectID为td对象，cellwidth为td对象的宽度
  function   GetDefineX(ObjectID,cellwidth)  
  { 
  if(cellwidth==null || cellwidth=='')
  cellwidth=0;	 
  var   iPositionX=ObjectID.offsetLeft;  
  while(ObjectID=ObjectID.offsetParent)  
  {  
  iPositionX+=ObjectID.offsetLeft;  
  }  
  return   iPositionX+cellwidth/2;  
  } 
    //获取td的y坐标，ObjectID为td对象，cellwidth为td对象的高度 
  function   GetDefineY(ObjectID,cellheight)  
  {  
  	if(cellheight==null || cellheight=='')
  cellheight=0;	 
  var   iPositionY=ObjectID.offsetTop;  
  while(ObjectID=ObjectID.offsetParent)  
  {  
        iPositionY+=ObjectID.offsetTop;  
  }  
  return   iPositionY+cellheight/2;  
  }  
 

 	
	//取消连线
	function undraw(jg){

	document.getElementById('draw_span').innerHTML='<font color="red">连线取消中，请稍候。。。</font>';
	
	jg.clear();
	is_draw=0;
	document.getElementById('draw_span').innerHTML= ' <img  src="../../images/drawline.gif" onclick="drawline();"  style="cursor:pointer; "></img>';
	}	
 


//根据td的className进行连线
function drawlinebytd(jg,class_name,color){ 
  		 
  			 		 
				jg.setColor(color); 			
				jg.setStroke(2);
				
			 var tds	= document.all.tags('td');
				var td1=null;
				var td2=null; 			
				for(var i=0;i<tds.length;i++){
					if(tds[i].className.indexOf(class_name)>-1){					
					td2=tds[i];				
				if(td1!=null && td2!=null){
					var x1=GetDefineX(td1,16);
					var x2=GetDefineX(td2,16)
					//判断从左往右还是从右往左,从而确定x1,x2的偏移量
					if(x1<x2)//从左往右
					 {
					 	x1=x1+4;
					 	x2=x2-4;
					} else {//从右往左
						x1=x1-4;
					 	x2=x2+4;
					}
					
					jg.drawLine(x1,GetDefineY(td1,96)+6,x2,GetDefineY(td2,96)-6); //根据y从上到下的顺序设置偏移量
			}
			td1 = td2;	
		}				
					
			}			 
			jg.paint();			
  	}
  
	
		function drawlinebytdmid(jg,class_name,color){ 

				jg.setColor("yellow"); 			
				jg.setStroke(2);
				
			 var tds	= document.all.tags('td');
				var td1=null;
				var td2=null; 	
				var x1=0;
				var x2=0;
				var y1=0;
				var y2=0;	
				var x1_sum=0;
				var x2_sum=0;
				var y1_sum=0;
				var y2_sum=0;
				var times=0;
					
				for(var i=0;i<tds.length;i++){
					if(tds[i].className.indexOf(class_name)>-1){					
					td2=tds[i];	
					times++;
					x2_sum+=GetDefineX(td2);
					y2_sum+=GetDefineY(td2);
					
					x2=x2_sum/times;
					y2=y2_sum/times;
								
				if(td1!=null && td2!=null){
					//jg.drawLine(GetDefineX(td1,16),GetDefineY(td1,20),GetDefineX(td2,16),GetDefineY(td2,20)); 
					jg.drawLine(x1,y1,x2,y2); 
			}
			
			td1 = td2;
			x1=x2;
			y1=y2;
	
		}				
			
			}			 
			 	jg.paint();			
  	}