Prepopulate visualforce apex:inputtext from URL parameter without using custom controller

URL …/apex/MyVFPage?AccountName=TheBlogReaders.com

AccountName in Parameter and pass the account value

here is a the right solution for your problem using VF page and Javascript
MyVFPage:
<apex:page standardController=”Lead”>
<apex:form>
<apex:inputtext  id=”jsName”/>
<script>
var jsName = “{!$Component.jsName}”;
</script>
</apex:form>

<script>
window.onload=function() {
document.getElementById(jsName).value = “{!$CurrentPage.parameters.AccountName}”;
};
</script>
</apex:page>