z-index problem with IE7

[yelliver]

I am getting z-index problem.I tried to put position:relative and z-index.But still the issue persist.Below is my Code:\[code\]<tr><td colspan="2"> firstname</td><td colspan="2"><table cellspacing='0' cellpadding='0' border='0' style='position:relative;float:left;'><tr><td width="25%"><div class="yui-skin-sam"><div id="myAutoComplete"> <input id="myInput" type="text"> <div id="myContainer"></div></div></div></tr></table></td></tr><tr><td colspan="2"> lastname</td><td colspan="2"><table cellspacing='0' cellpadding='0' border='0' style='position:relative;float:left;'><tr><td width="25%"><input type="text" name="lastName"/></tr></table></td></tr><tr><td colspan="2">address</td><td colspan="2"><table cellspacing='0' cellpadding='0' border='0' style='position:relative;float:left;'><tr><td width="25%"><input type="text" name="address"/></tr></table></td></tr>\[/code\]Please give some suggestions to resolve this issue.Thanks,Raj