Hi Kirasan,

  Hope this will help ..try below code


VisualForce page code:

<pre>
<apex:page controller="PageController">

    <apex:form >
        <apex:inputText id="sampleDateField" value="{!sampleDateField}" onfocus="DatePicker.pickDate(true, '{!$Component.sampleDateField}', false);"/>
        <c:DatePickerComponent dateFieldId="{!$Component.sampleDateField}" /> 
        <br/>
        <apex:commandButton value="Refresh" reRender="panel" action="{!refresh}"/>
    </apex:form>

    <apex:outputPanel id="panel">

            <apex:outputText value="{!sampleDateField}"/>

    </apex:outputPanel>  

</apex:page>
</pre>

Controller code:

<pre>
public with sharing class PageController {

    public Date sampleDateField {get; set;}

    public PageReference refresh() {
        return null;
    }
}
</pre>

Component page code:

<pre><apex:component controller="DatePickerController">
    <apex:attribute name="dateFieldId" required="true" type="String" description="id of field to set Date"/>

        [
        <apex:outputLink value="javascript:DatePicker.insertDate('{!currentDate}', '{!dateFieldId}', true);">{!currentDate}
        </apex:outputLink>
         ]

</apex:component>
</pre>

Component controller code:

<pre>
public with sharing class DatePickerController {
    public String currentDate{get; set;}

    public DatePickerComponentController() {
        currentDate = Date.Today().format();
    }
}
</pre>

output:



Thanks,
Allways Cool