The latest demonstration against Yemen's president on the streets of Sana'a marked a special milestone for the protesters who want him gone.Tuesday was the 100th day since the start of their campaign to oust Ali Abdullah Saleh."After 100 days we are more determined to overthrow the regime. We're not leaving the square until the regime is ousted," said protester Mohammad al-Rythan."We insist on our demands. It's impossible for us to give up our revolution, it's impossible that it will cool down," another protester, Sawsan, said.Opposition leaders are due to consider changes to a Gulf Arab plan intended to ease Saleh from power after almost 33 years.Saleh said in April he would sign the deal requiring him to step down a month later, then backed out in the final hours.The protesters say they won't accept any agreement that doesn't guarantee Saleh's immediate departure.So far Saleh's shown no sign that he's prepared to heed their demands.