相同相邻元素的位置

function getSameColStartEndPos(obj,colIndex)
{
var r = "";
var vCur = "$";
var vNext = "$$"
var start = "";
var end = "";
var isLastEqual = false;

for(var i = 1; i < obj.rows.length; i++)
{
vCur = getTDValue(obj,i-1,colIndex)
vNext = getTDValue(obj,i,colIndex);
if(vCur==vNext)
{
if(isLastEqual)
{
end = i;
}
else
{
start = i-1;
end = i;
}
isLastEqual = true;
}
else
{
if(i != 1)
{
if(isLastEqual)
{
r += start+','+end+'&';
}
}
isLastEqual = false;
}
}
if(r != '')
r = r.substr(0,r.length-1);
return r;
}