function doFormat(e, obj, mask, isString)
{
	if(obj.type!='text' && obj.type!='textarea'&&obj.type!='div') return;
	e=(window.event)?event:e;
	var key=(e.which)?e.which:e.keyCode;
	if(key==37||key==38||key==39||key==40||key==16	//arrow key
		||key==35||key==36||key==9					//home,end,tab
		||key==46||key==45||key==8					//del,insert,backspace
		)
		return;
	var val=obj.value;
	if(val.length>mask.length) val= val.substring(0,mask.length-1);

	var valChar = '#'
	var maskChar = '/'
	var i
	for(i=0;i<mask.length;i++){
		if(mask.substring(i,i+1)!=valChar){
			maskChar=mask.substring(i,i+1);
			break;
		}
	}
	//bo cac ky tu ngan cach va cac ky tu khac
	var valt=''
    var len=val.length;
	for(i=0;i<len;i++){
		if("1234567890".indexOf(val.substring(i,i+1))>=0){
			valt=valt + val.substring(i,i+1);
                       // alert(val.substring(i,i+1));
		}
    }
    //them cac ky tu ngan cach vao dung vi tri
    var j
    var rval=''
   	len=valt.length;
	switch(isString){
		case 1:		//gia tri kieu chu->can trai
			j=0;
		    for(i=0;i<len;i++,j++){
		    	if(mask.substring(j,j+1)==maskChar){
		    		rval=rval + maskChar;
		    		j++;
		    	}
		    	rval=rval + valt.substring(i,i+1);
		    }
                    break;
		case 0:		//gia tri kieu so->can phai
			j=mask.length-1;
		    for(i=len-1;i>=0;i--,j--){
		    	if(mask.substring(j,j+1)==maskChar){
		    		rval=maskChar + rval;
		    		j--;
		    	}
		    	rval=valt.substring(i,i+1) + rval;
		    }
	}
    obj.value=rval;
}